Home

XPS MultiQuant User`s Manual - The Molecular Materials Research

1. User s Manual Budapest 2011 Copyright 1999 2011 Miklos Mohai XPS MultiQuant is copyright by Miklos Mohai Microsoft MS MS DOS Visual Basic Windows and Windows NT are registered trademarks and trademarks of Microsoft Corporation Origin is registered trademark of OriginLab Corporation Pentium is registered trademark of Intel Corporation QUASES is trademark of QUASES Tougaard Inc No part of this document may be reproduced or transmitted in any form or by any means electronic or mechanical for any purpose without the express written permission of the author Content Introduction Legal Notes Installing XPS MultiQuant Uninstalling Technical Notes Using of the Program Starting XPS MultiQuant Setting Parameters Entering and Editing Input Data Calculator in the Input Windows XPS Reduced Data Exchange files Template Files Managing Results and Charts Saving and Printing Exporting Results Application of Structured Models Intensity Simulation Inelastic Mean Free Path Miscellaneous Remarks Step by Step Application Examples Applied Methods Homogeneous Model Cross Sections Angular Correction Correction for Elastic Scattering Inelastic Mean Free Path MFP Transmission Function Contamination Correction Multiline Approach Normalisation of the Results Models for Structured Surfaces Layers on Plane Model Layers on Sphere Model Layers on Cylinder Model Layers on Polyhedron
2. On the View menu click Parameters Click the Model tab and select the required Multiline approach method Average for good quality data Ebel when the weak lines are less reliable Notes If the element calculated by multiple lines is present in more than one chemical states data must be provided for all lines and all states e g S2s and S2p for both S and S 1 e totally four lines for sulphur Presenting Results in Various Forms On the View menu click Results Select the required result type in the dropdown list of the Composition window Double click the chemical symbols to omit an element for percentage type results or to set as basis element for ratio type results Click the up and down arrows of the Number box to change the quantity of basis atoms for ratio type results Select the Merge chemical states check box to sum the concentration of different chemical states of the same elements On the View menu click Chart 7 Inthe Composition window double click the label column headers to set X axis 27 8 In the Composition window double click the experiment numbers to omit an experiment from the chart Printing Reports l 2 3 4 5 On the File menu click Print Select the required data items to be printed Click the OK button If required select other result type On the File menu click Print Current Double click the Pending Page icon on the status bar or on t
3. Exponent 0 800 File name C Program Files MMQ Defaultmty Browse Edit Show Pririt Cancel Apply OK Type Select the type of the transmission function None no transmission correction FAT CAE fixed analyser transmission or constant analyser energy mode E FRR CRR fixed retarding ratio or constant retarding ratio mode E Exponential exponential function is applied with the given exponent E File exponential polynomial or rational function is applied Coefficients of the function are described in separate files File type Displays the type of the transmission function defined in the current transmission file Exponential Polynomial Rational Combined or Tabulated Exponent Set the exponent for the exponential type transmission function Filename Set the name of the transmission function file Browse Invokes the Open dialog box to browse and select transmission function file 93 Edit Opens the current transmission function file in the internal editor similar to Notes window To create a new transmission file or save the file with different name use Notepad or other simple text editor program Show Displays the transmission function as illustrated in the next figure S00 1000 Kinetic Energy ev Structure of the Transmission Files XPS MultiQuant analyser transmission files are simple ASCII files with mtr extensions They can be edited with Notepad and other tex
4. This software is provided as is The author makes no representations or warranties express or implied By way of example but not limitation the author makes no representations or warranties of merchantability or fitness for any particular purpose or that the use of the licensed software components or documentation will not infringe any patents copyrights trademarks or other rights The author shall not be held liable for any liability nor for any direct indirect or consequential damages with respect to any claim by the user or distributor of the software or any third party on account of or arising from this agreement or the use or distribution of the software Grant of License Permission to use copy and distribute this software and its documentation is hereby granted provided that 1 the use copying or distribution is not done for direct commercial advantage 2 any distribution of the software is on the same terms as in this License Agreement and each copy contains the copyright notices and the license agreement that appear in this software and supporting documentation and 3 any documentation or other materials related to such distribution or use acknowledge that the software was developed by Miklos Mohai To copy and distribute this software and its documentation in binary forms AS PART OF ANOTHER PRODUCT for commercial advantage is allowed only with the written permission of the author Installing XPS MultiQuant
5. For clean practically carbon free e g freshly cleaved or ion etched samples or on the contrary for strongly contaminated ones this factor does not provide proper correction In these cases method of Mohai 15 can be applied where c 1s a function of the normalised carbon concentration c a Ca b 37 Factors are calculated in two step iteration First Ca 1s calculated with c 0 next Ca values are used to calculate c factors by equation 37 This method is applicable up to 5 nm thickness of the contaminant layer To avoid the numerical misfit of the factors due to the various IMFP calculation methods providing either the absolute or a proportional value in the contamination correction term of 46 equation 6 instead of the applied IMFP a value relative to the carbon is used 38 R exp c j Ac 38 where Ac is the inelastic mean free path of the Cls photoelectron line in the sample The user can also set the correction factors manually 1 e enter values proportional to the thickness of the contaminant layer for each experiment Multiline Approach The influences of statistical and systematic errors of XPS quantification can be reduced by introducing as many photoelectron lines as possible for each element and calculating the average of the results evaluated separately It can be done by simply averaging the unnormalised results for all lines of each element as shown by equation 39 Ni DN 39 k
6. Number of quantification models Number of concentration result types Maximum number of elements Maximum number of experiments Maximum number of layers Maximum of multilayer factor Maximum number of transmission file items Maximum order of transmission polynomial Maximum length of label text characters Maximum length of notes text characters Largest integer number allowed Largest real number allowed 120 103 1 068 2 475 13 20 40 40 15 32 768 32 767 3 4 10 Literature 1 D Briggs M P Seah Eds Practical Surface Analysis Volume 1 Auger and X ray Photoelectron Spectroscopy John Willey amp Sons Chichester New York Brisbane Toronto Singapore Salle Sauerlander Aarau Frankfurt am Main Salzburg 1990 2 J C Rivi re S Myhra Eds Handbook of Surface and Interface Analysis Marcel Dekker Inc New York Basel Hong Kong 1998 3 S Evans R G Pritchard J M Thomas Relative Differential Subshell Photoionization Cross sections Mg Ka from Lithium to Uranium J Electron Spectrosc Relat Phenom 14 1978 341 4 R F Reilman A Msezane S T Manson Relative Intensities in Photoelectron Spectroscopy of Atoms and Molecules J Electron Spectrosc Relat Phenom 8 1976 389 5 H Ebel M F Ebel A Jablonski On the Influence of Elastic Scattering on Asymmetric XP signal Distribution J Electron Spectrosc Relat Phenom 35 1985 155 6 W Hanke H Ebel M F Ebel A Ja
7. with 15 elements the results could be displayed as atomic atomic ratio oxide ratio or mass Two label sets Name and Time could be assigned to the experiments Library with three cross section sets Evans and Scofield Meg Ka and Al Ka was also included The program could apply a few structured models Layers on Plane and Layers on Sphere with maximum three layers as well but only with interactive manual parameter fitting It had no graphic capabilities and help system was not available LAYERS A DOS program to calculate the intensity and intensity ratio of electrons excited from planar or spherical samples covered with overlayers Maximum three layers with 6 elements could be calculated QUANT 140 This quantification program could handle a simplified homogeneous model It was an overlay program system consisting of five programs QUANT 140 WEIGHT 140 EDIT 140 FACTOR 140 ENERGY 140 written for a Texas Instruments TI 59 pocket calculator with magnetic card reader and printer One experiment with 14 elements could be calculated results could be expressed as atomic or atomic ratio A real gem 119 Specifications Library Specifications Number of element entries Number of photoelectron line entries Number of cross section and sensitivity factor sets Number of cross section and sensitivity factor data items Number of asymmetry coefficient parameter sets Number of geometry correction factor sets Program Limitations
8. 13 functions or the combinations of the above 14 optionally with different coefficient sets for different kinetic energy ranges In the latter cases transmission is calculated by equations 31 34 T aj a E 2 31 T lt a aj Et a E 4a E 32 T lao aye ane aE aye 1 b e bze b3 bye 33 T x Ap ay page Pane ayge bE 34 For the last two equations is calculated by e E 1000 1000 35 The coefficients of the equations with the corresponding limits of energy ranges are stored in separate files See chapter Transmission Tab in Program References When the transmission function is not available analytically it can be provided in tabular form as well The actual transmission factors are calculated by linear interpolation There is no separate term in the program to describe the detector sensitivity as the function of the kinetic energy If this factor cannot be neglected e g in the case of fixed retarding ratio analyser mode it should be incorporated into the transmission function Contamination Correction The surface contamination of the samples which usually consists of carbonaceous material can be taken into account by various methods Evans 3 uses the expl c E 5 36 factor with a constant c 14 3 value It can be applied for most of the cases when the sample is stored in ambient and a saturated level of contamination is developed
9. Highlights the entire Notes text 73 Format Menu Notes window File Edit Help Word Wrap Font Word Wrap Wraps text to the width of the Notes window It does not affect the way text appears when it is printed A check mark appears when word wrap is turned on Font Changes the font style and size of the Notes window An example of how the selected font will look appears in Sample The selected font and its size are stored with the default parameters while other elements style colour etc are not retained Help Menu Notes window File Edit Format Help Help Invokes the help topic of the Notes window Pop up Menu input windows Cut Cells Copy Cells Paste Cells Unda Paste A pop up menu activated by a right mouse click is available in the input windows Elements Intensity IMFP amp Contamination Model to cut copy and paste the content of the active cell or range of cells to or from the clipboard Data can be exchanged within XPS MultiQuant or between other Windows applications 74 When the pop up menu commands are invoked in one of the mentioned windows only the selected cells are affected Multiple rows and columns can be selected by clicking one of the corners and dragging to the opposite corner or by pressing the SHIFT ARROW keys If there are more cells in the selected range than are in the clipboard the remaining cells are cleared If there are more cells in the clipbo
10. L 0 8 A T exp c A 6 where is the measured integral intensity of element i and F is the sensitivity factor which consist of the following terms g 1s the relative photoionisation cross section function of photoelectron transition L g f 1s the angular correction factor function of the asymmetry parameter p and the direction of observation 4 is the IMFP function of the matter and kinetic energy 7 the transmission correction function of the kinetic energy and c 1s the correction for surface contamination proportional to the layer thickness Each term of the sensitivity factors can be controlled independently When None is selected in the program for any of the above terms the corresponding value is set to 1 Cross Sections Experimental cross section data of Evans 3 were measured with 90 excitation analyser angle To correct it to the 4r sr solid angle the equation 7 is applied which is derived from equation 11 for 90 angle eee ee 1 8 4 where is the total relative photoionisation cross section og 1s Evans cross section and p is the asymmetry parameter Wagner s sensitivity factors for the secondary lines are multiplied by 0 9 for Mg Ka and by 1 1 for Al Ko excitation 1 The primary lines are the strongest ones while secondary lines are the 2s 3p 4p 4d except from Dy to Lu and 5d lines When the experimental cross section or sensitivity factors are used some data may be missing
11. On the Tools menu click Simulation U In the Intensity Simulation window select the experiment number where the simulated results are stored 4 Enter the thickness of the layers and the coverage 5 Click the Calculate button 6 Repeat points 3 5 to calculate further experiments 7 Click the OK button to finish simulation Notes e Ifthe status of the selected experiment is not Empty previous entered intensity data will be overwritten 32 This chapter describes and gives hints on the sample XPS MultiQuant data files included in the distribution kit These files are usually located in the Program Files XMQ Samples folder These examples illustrate the various features of the program A brief description is also included into the Notes text of each file Example files have some magic when opened by the Open Example command The Notes window and other subwindows are activated Application Examples automatically and the result format is set as appropriate for the selected data Contact Contact mqd These XPS spectra were recorded on an electrical contact prepared on a silicon wafer from titanium and silver The sample was heat treated causing diffusion of the components The upper layers were oxidised and the top surface was contaminated by carbon Ion etch series were performed by 2 keV Ar ions in 2 min steps 16208 Soga 60ga 4099 2000 Ag 3d 8800 4008 2888 ENSA
12. di d2 The description of photoelectron intensity from a cylindrical surface covered by overlayers 1s similar to the spherical ones 18 In this case the shapes of the projected surfaces are rectangles instead of annuli for spheres see the figure above and in closely packed arrangement the lower rows are not visible partially even in the case of crossing cylinders Thus the way of the calculation for spheres and cylinders performed by the program are similar but the values of the geometry correction factors are different This kind of sample must also be observed from the direction of the surface normal Layers on Polyhedron Model Go G Go PE s UEN i 0 d d d2 E 7 gt Rough surfaces with macroscopic or microscopic structures can usually be modelled by small planar units at different angles 1 e facets of one or several types of polyhedra The Layers on Polyhedron model 19 allows defining various surface geometry From the point of view of quantification only the relative sizes of the projected areas and the tilt angles of the different facets measured from the base plane normal are relevant The projection plane is the virtual base plane of the sample supporting the polyhedra The calculation of photoelectron intensity values excited from a polyhedral surface covered by overlayers is similar to the calculation of other structured models but while in case of spherical and cylindrical models the geometry
13. f7 2 binding energy components respectively This approach provides proper base for the IMFP and transmission corrections The values although usually refers to elemental states are precise enough only for transmission and IMFP approximation Never use them for chemical state determination Cross Sections and Sensitivity Factors Five different theoretical and experimental data sets are available in the library for most of the elements and photoelectron lines Any other cross section or sensitivity factor values can be entered manually All data are based on peak areas and not peak heights The data of Scofield 28 are theoretically calculated cross sections using relativistic single potential Hartree Slater atomic model Separate sets are available for Mg Ka and Al Ka excitation sources Data are relative to Cls 1 22200 barn and 13600 barn respectively 63 XPS MultiQuant chooses the data set according to the selected excitation source When the source energy is specified by the user the Al Ka set is selected Lines from Is to 4f when applicable are included in the library If experimental data are available from Hg to U the 5d lines are also included The data of Evans et al 3 are experimentally based relative differential cross sections relative to Fls 1 Data were measured with Mg Ka radiation fixed retard ratio FRR CRR analyser mode and at 90 analyser excitation angle The angular dependency of data was not e
14. location matrix Error N error description An unexpected fatal program error occurred The program stops Report the error number the location window the command used and other circumstances to the author Error in XPS Reduced Data Exchange file filename Loaded data may be incorrect There are one or more errors in the loaded XPS Reduced Data Exchange file Several other error messages may follow this message Consult the manufacturer of the source application which generated the file Information and software tools to analyse the invalid file are available at the homepage of XPS MultiQuant Error description occurred at fitting of parameters N Check model and refine initial data Unexpected program error occurred during the least square fitting at step N Fitting is abandoned Error description occurred at model calculation N Unexpected program error occurred during the calculation of model intensity Estimate initial layer thickness values before Autofit Guess and enter initial values for layer thickness and coverage before invoking the Autofit procedure The Qsum of the initial data should be 50 or less File not found The specified file cannot be found in the current folder 109 File shorter than expected The number of parameters read from the data file or transmission file is fewer than expected by the program The file may be correct but check all parameters and enter missing ones Consult chapter Struct
15. model Redesigned Layer Calculation window New items in Parameters window New data file version 2 2 The Data Wizard can be started automatically Minor bugs were corrected An error of loading results of structured models may cause crash is corrected The annoying error of the Paste Table command inserting non printable characters into cells was corrected The SHIFT Copy Table command was implemented A window sizing error causing crash was corrected 117 5 01 5 00 4 10 4 00 3 00 2 10 2 01 2 00 1 20 The improper handling of file extensions of Template files and the error in Model Layout window when the polyhedral model is not defined were corrected Enhanced checking of equations at island type models using Angle dependent experiments The Layers on Polyhedron model type was added The Multiline approach for the homogeneous model was added Reorganised Parameters and Notes windows Internal editing of transmission files The Template file type was introduced Improved error checking of element data Data entry accelerator in Element window Rewritten enhanced window handling and auto manual resizing Enhanced HTML based help system Cell copy from Composition former Results window New data file version 2 1 Several new messages New application examples Minor bugs were corrected New chapters in the Users Manual Template Files Multiline Approach Layers on Polyhedron Model Polyhedron Edito
16. press ENTER after each number the results of the calculation are displayed in the first column of Calculated relative intensity columns The Diff column shows the percentage difference between the calculated and measured intensity Negative Diff value means that the calculated intensity is lower than the measured Diff is displayed only when smaller than 100 The Qsum row shows the sum of the squares of the differences indicating the precision of the fit When all of the new layer thickness values are entered the previously calculated intensity values are shifted to right preserving the two previous sets for comparison To minimise the difference between the measured and calculated intensity the user can vary the layer thickness manually or can use the automatic least square fitting feature The Coverage row is displayed only in case of sland type models Experiment Selects the next or previous experiment for calculation without leaving the Layer Calculations window The result of the current experiment is stored in the Layer Thickness window This item is not available in case of angle dependent experiment set Autofit Starts the automatic least square fitting procedure of model parameters Cancel Closes the Layer Calculations window without saving last results OK Closes the Layer Calculations window and stores the last results into the Layer Thickness window 85 R fe Tens E measured Relative intensit
17. 73 74 75 76 81 87 101 106 Powell C J 22 29 44 64 83 91 115 118 121 122 123 Print Current command 17 28 67 81 87 Print Options window 17 67 103 Print window 17 67 106 Printer 10 104 114 Q Qsum 20 24 30 39 49 85 109 114 R Radius 29 52 53 58 60 88 89 98 110 111 112 Rational NPL function 9 46 93 94 95 117 Registry entries 8 Reilman R F 26 43 64 92 114 121 Results type Atomic 16 47 80 129 Atomic ratio 16 80 Mass 16 48 80 Mass ratio 16 80 Oxide mass 16 80 118 Oxide mass ratio 16 80 118 Oxide molar 16 80 Oxide molar ratio 16 37 80 S Save Data As 67 Scaling 9 34 42 43 64 90 111 Scofield J H 63 64 89 119 123 Seah M P 22 25 29 44 45 79 91 110 115 1182 121122 Sensitivity factor 13 23 26 42 47 49 63 64 89 90 120 Sequence number 16 20 28 31 68 81 84 85 87 99 Shortcut 12 17 66 67 Shortcut keys 107 Show 91 94 Simulation 21 32 39 71 102 110 117 Source energy 26 64 88 119 Special State entries 78 Spherical surface 19 39 52 53 54 55 87 119 Splitting 42 43 90 111 State column 14 21 32 49 77 78 96 State entries special 78 Status bar 13 17 27 28 67 88 103 106 Structured models 16 22 24 25 55 62 83 89 108 112 114 115 117 118 119 T Take off angle 21 24 39 53 55 56 60 62 78 99 100 108 Tanuma S 22 29 44
18. 80 Oxide mass 16 80 118 Oxide mass ratio 16 80 118 Oxide molar 16 80 Oxide molar ratio 16 37 80 Notes window 16 17 33 66 70 73 74 94 108 118 O Omit element 16 24 Omit experiment 16 81 Open data 16 17 20 71 72 101 107 118 Origin 2 18 Overlayers 19 20 21 22 41 49 51 52 54 55 57 60 61 97 112 119 Ox oxide chemical state 21 32 78 111 Oxidation state 48 80 Oxide mass 16 80 118 Oxide mass ratio 16 80 118 Oxide molar 16 80 Oxide molar ratio 16 37 80 Oxide Layer model 21 32 37 38 61 78 97 111 112 118 Oxygen balance 16 34 37 48 80 P Parameters Angular tab 92 Contamination tab 96 Cross Section tab 89 General tab 88 IMFP tab 90 Labels tab 99 Model tab 97 Transmission tab 46 93 Parameters window 14 16 19 20 21 22 24 36 38 39 69 70 71 78 79 81 82 106 108 110 111 113 114 115 116 117 118 Pasting 15 17 75 Pending page 13 17 66 67 81 87 106 Penn D R 22 29 44 83 91 115 118 122 Photoelectron intensity 19 21 49 51 52 54 55 65 Photoelectron line transition 42 Photoelectron lines 27 37 41 47 63 64 70 77 78 109 111 112 120 Photoionisation cross section 6 13 21 23 26 34 35 41 42 43 49 57 62 63 64 89 90 111 119 120 Polyhedral surface 55 118 Polyhedron Editor 31 98 100 101 118 Polymers 23 36 44 91 110 Polynomial 46 93 94 95 120 Pop up menus 15 17
19. 83 91 115 118 122 Template files 9 10 16 66 67 106 118 Tilt angle 21 24 39 53 55 56 60 62 78 99 100 108 Title 13 16 27 66 67 87 88 105 106 108 116 119 Tools menu 70 Tougaard S 2 49 TPP 2M formula 44 64 71 91 Transmission function 6 10 11 14 21 26 35 42 45 46 49 58 62 63 64 93 94 95 101 106 108 110 111 113 114 116 117 118 120 Transmission function files 10 11 94 106 118 U UNIFIT combined function 9 93 94 95 117 122 Uninstalling 8 V Valence 45 63 64 71 77 83 115 Valence electrons 45 64 71 83 115 Vars nyi G 65 122 124 View menu 69 W Wagner C D 23 42 64 89 123 Windows 15 17 22 66 68 71 72 74 75 77 81 105 113 117 119 Chart 16 20 69 75 81 86 99 118 Composition 16 27 28 71 80 Elements 13 14 21 27 32 37 49 66 69 70 115 IMFP amp Contamination 14 69 71 79 83 91 96 Intensity 14 16 21 28 39 69 75 99 102 108 110 116 117 Intensity Simulation 21 32 39 71 102 110 Layer Thickness 20 30 31 39 69 75 81 84 85 87 Model 19 20 21 29 30 31 38 69 70 71 82 83 84 98 111 112 113 115 116 119 Model Layout 17 20 67 69 76 84 87 117 118 Model Summary 70 83 117 Notes 16 17 33 66 70 73 74 94 108 118 Parameters 14 16 19 20 21 22 24 36 38 39 69 70 71 78 79 81 82 106 108 110 111 113 114 115 116 117 118 Print 1
20. Default is the Windows default printer Page Set the orientation and margins of the page The size of the paper can be set in the Control Panel of the Windows operating system Margins can be varied from 0 5 to 5 cm Font Select or set the name and size of the font for printing In the Name list all fonts of the selected printer are shown The font size can be selected between 4 and 36 points An example of how the font will look also appears it may be improper when no matching screen font is installed Cancel Closes the window without changing options OK Closes the window and accepts new options 104 Data Wizard This wizard helps you to fill the tables of XPS MutiQuant i Start wizard automatically W Always on top ss Die The Data Wizard window helps the unfamiliar users walking through the different phases of setting up an XPS MultiQuant calculation by giving step by step instructions The upper panel shows the title of the current step while the lower panel provides a brief description and also an error message if necessary Follow the instructions of the wizard enter the required data then press the Next button When an error 1s occurred a warning signal is displayed and beside the standard messages of the program the wizard gives the short explanation of the problem Press the Back button and revise the entered data Consult the online help or the User s Manual for hints The Back and Next buttons
21. Model Layers on Nanotube Model 37 Island Type Models 60 Oxide Layer Model 6l Library Data 63 Chemical Elements 63 Photoelectron Lines 63 Cross Sections and Sensitivity Factors 63 Average Scale Factors 64 Asymmetry Parameters 64 Number of Valence Electrons 64 Geometry Correction Factors 65 Program References 66 Menu Commands 66 File Menu 66 Edit Menu 68 View Menu 69 Tools Menu 70 Windows Menu 71 Help Menu 72 File Menu Notes window 73 Edit Menu Notes window 73 Format Menu Notes window 74 Help Menu Notes window 74 Pop up Menu input windows 74 Pop up Menu Chart window 75 Pop up Menu Model Layout window 76 Windows 71 Elements 71 Intensity 78 IMFP amp Contamination 79 Composition 80 Chart 81 Model 82 Model Summary 83 IMFP amp Contamination of Structured Models 83 Layer Thickness 84 Layer Calculation 84 Model Layout 86 Parameters 88 Polyhedron Editor 100 Notes 101 Intensity Simulation 102 Print 103 Print Options 104 Data Wizard 105 Open Save As 106 Status Bar 106 Keyboard Commands Shortcut Keys Editing Keys Menu Access Keys Messages Release Notes Specifications Literature Contact Index 107 107 107 107 108 117 120 121 124 125 Introduction Quantitative evaluation of XP spectra is a major issue in surface characterisation Numerous methods models and data sets were developed and published but usually only the simplest ones are built into the commercial data systems used for
22. Phys Rev B 68 2003 165401 T A Carlson Basic Assumptions and Recent Developments in Quantitative XPS Surf Interface Anal 4 1982 125 B R Stohmeier An ESCA Method for Determining the Oxide Thickness on Aluminium Alloys Surf Interface Anal 15 1990 51 R C Weast Ed CRC Handbook of Chemistry and Physics 67th edition CRC Press Inc Boca Raton Florida 1987 XSAM 800 Data Book Kratos Analytical Instruments Manchester 1982 C D Wagner C J Powell J W Allison J R Rumble NIST X ray Photoelectron Spectroscopy Database Version 2 0 National Institute of Standards and Technology Gaithersburg MD 1997 J H Scofield Hartree Slater Subshell Photoionization Cross sections at 1254 and 1487 eV J Electron Spectrosc Relat Phenom 8 1976 129 C D Wagner L E Davis M V Zeller J A Taylor R H Raymond L H Gale Empirical Atomic Sensitivity Factors for Quantitative Analysis by Electron Spectroscopy for Chemical Analysis Surf Interface Anal 3 1981 211 V I Nefedov N P Sergushin I M Band M B Trzhaskovskaya Relative Intensities in X ray Photoelectron Spectra J Electron Spectrosc Relat Phenom 2 1973 383 V I Nefedov N P Sergushin Y V Salyn I M Band M B Trzhaskovskaya Relative Intensities in X ray Photoelectron Spectra Part II J Electron Spectrosc Relat Phenom 7 1975 175 123 Contact The author would be indebted if you send him comment
23. Samples Program Files XMQ Samples Program Files XMQ Samples Program Files XMQ Samples Program Files XMQ Samples Program Files XMQ Samples Program Files XMQ Samples Program Files XMQ Samples Program Files XMQ Samples Program Files XMQ Samples Program Files XMQ Samples Program Files XMQ Samples Program Files XMQ Samples Program Files XMQ Samples Program Files XMQ Samples Windows System Windows System Windows System Windows System Windows System Windows System Windows System Windows System Windows System Windows System Windows Example data file Example data file Example data file Example data file Example data file Example data file Example data file Example data file Example data file Example data file Example data file Example data file Example data file Example data file Example template file Example template file Reduced Data Exchange file Transmission file Transmission file Transmission file Transmission file Transmission file Excel 2000 workbook Word 2000 document Common Controls Common Dialog Control Graph Control Graphic server AutoGraph Graphic server library FlexGrid Control Visual Basic Virtual Machine Sysinfo Control Tabbed Dialog Control Uninstall program Registry Entries The first two entries store the default and initial settings of the program The subsequent entries describe the XPS MultiQuant data transmission and templates file types and also the XPS Reduced Exch
24. TORS on Roe Od eR R NOREA n wi secre AYA Myre ATA EAN iS R ANN Aes Onan Ng Soa Ay a gt Caer a ENA CONAN FR NRI ERP OE Of SSI NSS OG eS OEE a On ee ENO GOOLE ApS GY GIL ERN NNN Q RT a 375 378 365 360 BE 6088 42808 r 2820 33 38 Si2p 536 534 532 WV SGA KRAVIS IO 530 528 526 524 B E ow Hn eaters Q TUN 9 y earn LHR l VINY w A OAA SAP hep ADA Yi NO Soa ape The ion etch depth profile reflects the changes seen on the previous figure Beside the intensity height changes of the lines consider alterations in FWHM as well this explains the shallower concentration differences visible in the T1 profile The reduction of the system can be seen from not only the chemical shift changes but the decreasing oxygen balance as well Atomic Time min This example illustrates of the simple handling and fast calculation of large data sets Test the different results formats When ratio types are used be careful of the zero intensity data The printed depth profile was prepared by Microsoft Excel as demonstrated by the ContactProfile xls file Nitrocarburised Steel Steel mqd These data were recorded on steel samples nitrocarburised by plasma treatment PN and Plasma Immersion Ion Implantation QNC after Ar ion etch These samples contain carbon thus the automatic contamination correction cannot be used Instead a moderate ion etch was appli
25. XPS MultiQuant can be used under Windows 2000 Windows XP Windows Vista and Windows 7 operating systems Although it is not tested on Windows 95 98 ME and NT it is expected to run on these systems as well You cannot simply copy the files from the distribution media to your hard disk You must use the Setup program to decompress and install files into the correct folders Before running setup remove any previous installations of XPS MultiQuant To install XPS MultiQuant on your computer Download the XPS MultiQuant distribution kit from the Internet Decompress the downloaded ZIP archive into an empty folder Run the Setup exe program from this folder Follow the instructions of the setup program If an appropriate Service Update 1s also available with the same major version number download and decompress the archive and follow the instructions of the attached Read Me file Uninstalling If you for any reason do not want to use XPS MultiQuant any more you can fully remove it easily To uninstall XPS MultiQuant from your computer Press Start button Select Settings Control Panel Double click the Add Remove Programs icon Select XPS MultiQuant from the list Press the Add Remove button Follow the instructions of the removal program The names of the Control Panel items may vary in the different versions of the operating system If the program cannot be removed automatically e g the St6unst log file was accidentall
26. and a warning tone is sounded The following table shows some examples for valid and invalid expressions Valid expressions Invalid expressions 23 123 246 123 lee 12 Two exponent signs 123 456 333 12e1 2 12 Digit separator in exponent 12 3 123 35 3 12 34 12 Two digit separators 456 12 38 12e 12 12 Two signs in exponent 123 4 1 5 185 1 1237 Right hand operand missing 12 3e 12 4e 10 307 5 12e 12 Digit in exponent missing 2 46E12 1 23EI2 2 123 4 123 Two operators 1 2e 12 2e12 2 4 A123 Left hand operand missing XPS Reduced Data Exchange files XPS Reduced Data Exchange files are designed to transfer reduced data peak position FWHM integral intensity etc from spectral processing programs to other programs e g for looking up line positions in a database calculating IMFP for the determined energies or performing special quantification The XPS Reduced Data Exchange files are unformatted character files with defined structure They can be prepared on various computers under DOS Windows Unix Linux and Macintosh operating systems and can be read without any previous conversion Interpreting of version 1 1 XPS Reduced Data Exchange files is fully implemented in XPS MultiQuant Files can be opened like the standard data files by the File Open menu command or the source application can invoke XPS MultiQuant directly and pass the file as a parameter Transferring of data
27. can be routinely applied for simple quantification ion etch depth profile etc and it gives immediate results The advanced features layer thickness calculation on flat or curved surfaces cannot be addressed directly because these features require deeper user interaction anyway 15 Template Files XPS MultiQuant template files make the work easier if you frequently perform the same quantification on similar sample series Template files as data files store all basic data model definition title and notes but do not save intensity values labels and results for the structured models To save the current data set as template file invoke the File Save as command and select the XPS MultiQuant Template Files mqt file type You can open the template files as the data files by the File Open command by drag and drop the file into the main window or by double click it When a template file is loaded the ntensity window appears immediately Managing Results and Charts Display the Composition window by the View Results command Results can be presented in eight different forms Atomic Atomic ratio Oxide molar Oxide molar ratio Mass Mass ratio Oxide mass or Oxide mass ratio If you select one of these forms from the dropdown list the data in the table are recalculated immediately When the percentage type results are selected you can omit any element from the 100 sum just double click the element symbol The omi
28. errors were corrected Reorganised Parameters window Results windows were renamed New data file version 2 3 Several new messages Minor bugs were corrected New chapters in the Users Manual Intensity Simulation Layers on Nanotube Model The following rare errors were corrected when an XPS Reduced Data Exchange file is opened and the default model type 1s not Homogeneous an error occurred When a modified example file is saved always the Save As command invoked When the Composition former Results window is minimized and a new line is inserted into the Elements or Intensity window the program crashed Sizing errors of Chart and Transmission windows were corrected The following very infrequent error was corrected when an XPS Reduced Data Exchange file contains unidentifiable element entries the sum of the percentage composition may exceed the 100 The Open Example command was added The magic of example files was implemented The omit state of elements can be changed in the Layer Calculation window When a line cannot be found in the library available lines are listed in the error message window Redesigned Model Summary window The Save As command offers the user s document folder New transmission file types were implemented NPL Unifit Table Poly 0 Improved IMFP calculation for the Homogeneous model Gries method extended Separate options Displaying the calculated IMFP values of the Homogeneous
29. from the data set In these cases for rough approximation splitting and scaling of experimental data are implemented in the program Cross section of the doublet lines of the experimental data can be split to its components e g 3d to 3d3 2 and 3ds 2 using the corresponding theoretical ratio equation 8 or by the nominal ratio values 1 2 for p lines 2 3 for d lines etc O Of 7 th ex _ EX 0 Q Oj 0 sum th th O1 tO9 42 where o is the split experimental cross section of either doublet component o is the theoretical cross section of the same doublet component and o the experimental cross section of the doublet line When the data for a required line is not included in the experimental data set the user may try to scale the available theoretical data to the applied set This can be done by the ratio of the closest line equation 9 or by an average factor equation 10 ov h a o 9 o ex h Ij egt yo 10 J j Oj Although splitting usually provides reliable data scaling is considered as a rough estimation only Use scaled data only when there is no other possibility and restrict use for minor components The closest line can be as far as 1000 eV from the basis line so try both scaling methods and choose the more probable one Angular Correction This correction is calculated by the method of Reilman et al 4 using equation 11 ELE ee ee ok P eos Wy 11 where p is the as
30. of the Jacobian matrix is at the tolerance specified in the program in absolute value It means possible numerical convergence but the precision of calculation 1s limited or the convergence is very slow 115 The thickness of the modified layer is higher than the thickness of the nanotube wall The Modified tube layer feature was selected where the thickness of the modified layer cannot be larger than the original wall thickness 1 e the wall is transformed to layer Enter smaller value or unselect this feature The solution is orthogonal to the columns of the Jacobian matrix to machine precision The solution vector is orthogonal to the columns of the Jacobian matrix to machine precision The task cannot be solved with the present initial data The tolerance limit is reached No further improvement in the approximate solution is possible The relative error between two consecutive iterates is at the tolerance limit specified in the program 1 e there are no further changes in the approximate solution The tolerance limit is reached No further reduction in the sum of squares is possible Both the actual and predicted relative reductions in the sum of squares reached the tolerance limit specified in the program The transmission file is not found in its specified location path but found in the data file application folder Do you want to keep the original invalid path XPS MultiQuant stores the full path of the transmission file in
31. that the simulation can be used only for layered structures However intensity data of a homogeneous sample can be calculated as well Define the required composition as the bulk of the model define one any kind of layer and set its thickness to zero Again surface contamination can be realized by a carbonaceous layer 21 Inelastic Mean Free Path The inelastic mean free path values are one of the most important parameters of the quantitative XPS calculations thus they should be selected very carefully The recommended sources of IMFP data are in this hierarchy measured values from the reliable literature and databases experimentally based calculated values from the literature and databases values calculated by predictive formulae 9 values calculated by predictive formulae within XPS MultiQuant The application of the IMFP values is slightly different for the homogeneous and the structured model calculations For the homogeneous model when the relative composition of the sample is calculated instead of the absolute IMFP values numbers proportional to the IMFP values can be used Consequently several straightforward methods are available like the simple exponential approach or Jablonski s 7 method Obviously the actual IMFP values can also be used Explicit method XPS MultiQuant applies the selected method on the fly for the calculations Conversely for the structured models when the thickness of the overlayers is
32. the Sphere or Cylinder radius to 0 set the Multilayers to 1 Click the OK button On the View menu click Model Enter a descriptive name for each layer Layer 1 is the topmost one and the bulk Enter the density g cm for each layer and the bulk Specify the composition of the layers enter the number of atoms for each element representing the atomic ratio like the stoichiometric coefficients for each layer including hydrogen atoms starting form the 0 No H row Values can be integers or real numbers On the Tools menu click Model Calculate Molecular Weight On the Tools menu click Model Mark Unused IMFPs Enter IMFP values for each layer and the bulk for the kinetic energy of the lines of the elements starting form the 1 IMFP row Fill all unmarked cells On the Tools menu click Model Test Model Correct the listed errors if any Notes When the Layers on Nanotube model is used both the Sphere or cylinder radius and the Tube inner radius must be entered The geometry correction factors of the Layes on Polyhedron model should also be defined as described later Calculating IMFP for Structured Models On the View menu click Parameters Click the IMFP tab Select the required Method Seah Dench Tanuma Powell Penn Gries Cumpson Seah Click the OK button On the View menu click IMFP amp Contamination Double click the Material class row for each layer and the bulk until the proper class 1s di
33. the data files If the transmission file is not found at the given location e g it was moved or the path was renamed the program attempts to find a file with similar name first in the folder of the current data file next in the folder of the application usually Program Files XMQ Select Yes to keep the original improper path stored in the data file or No to store the new path When the transmission file is found in either of the default locations always verify whether its content appropriate for the present calculations Time data not set The Tools Create Depth Scale command was selected but the Time labels are empty Select Time labels and enter data in the Intensity window Title must be entered No title entered in the General tab of the Parameters window Enter title now Too many elements omitted The described model is defined but with the elements marked as Omit in the Model window it became ill defined Remove the omit marks until the system becomes defined again Transmission file not found The specified transmission file cannot be found Use the Browse button to locate the file manually 116 Release Notes 7 00 6 13 6 12 6 11 6 10 6 00 5 04 5 03 5 02 The Layers on Nanotube model was added including the Modified tube layer variant The single row variant of the Layers on Sphere model was implemented Intensity simulation was implemented The Model Layout window was enhanced drawing
34. the everyday work The aim of developing the XPS MultiQuant program was to give a practical and universal tool to the surface chemists for obtaining the correct analytical results in most of the cases The program applies the classic approach of the quantitative calculations requiring the input of the integrated intensity of the measured XPS lines All of the usual factors and correction methods including calculated and experimental cross section values from several sources asymmetry parameter analyser transmission IMFP contamination of the adventitious carbon can be applied and controlled independently The necessary basic data for calculations for elements XPS lines etc are integrated into the main library Calculation of several samples or experimental data sets e g series of 1on bombardments or heat treatments etc can be done together Results can be presented in various forms like atomic atomic ratio oxide molar ratio etc and can be printed and charted The sample geometry model can be selected from several options beside the frequently applied infinitely thick homogeneous sample model other ones for layered structures both on flat and curved surfaces are also available Legal Notes XPS MultiQuant is Copyright 1999 2011 by Mikl s Mohai All rights reserved Copyright The software library help files install program and its source code are a property of Miklos Mohai Disclaimer of Warranty
35. window 74 Help menu 72 74 Help Menu Notes window 74 Tools menu 70 View menu 69 Windows menu 71 Merge chemical states 16 27 80 Messages 108 Mg Ko excitation 23 42 64 Model Layout window 17 20 67 69 76 84 87 117 118 Model Summary window 70 83 117 Model window 19 20 21 29 30 31 38 69 70 71 82 83 84 98 111 112 113 115 116 119 Models 6 19 20 21 22 24 29 37 49 50 55 60 62 83 85 87 98 118 120 Homogeneous 13 19 22 24 25 26 29 39 41 87 89 97 98 113 117 Islands on Cylinder 60 118 Islands on Plane 60 99 119 Islands on Polyhedron 60 Islands on Sphere 60 118 Layers on Cylinder 54 97 Layers on Nanotube 29 40 50 57 87 97 117 Layers on Plane 37 38 39 51 97 99 112 119 Layers on Polyhedron 31 55 87 97 98 118 Layers on Sphere 39 52 97 117 119 Oxide Layer 21 32 37 38 61 78 97 111 112 118 Modified tube layer 40 50 98 115 117 Mohai M 2 7 13 14 23 26 36 46 65 78 96 114 122 123 124 mqd file extension 9 10 11 12 17 33 34 35 36 37 38 39 40 106 110 mat file extension 9 10 16 106 128 mqx file extension 9 10 106 mtr file extension 9 10 94 106 Multiline Approach 14 26 27 35 47 98 109 118 121 N Native oxide 24 37 38 Nefedov V I 64 89 123 NLP rational function 9 46 93 94 95 117 Normalisation 46 47 48 115 118 Atomic 16 47 80 Atomic ratio 16 80 Mass 16 48 80 Mass ratio 16
36. 118 J Jablonski A 22 44 79 91 121 127 K Keyboard commands 107 Kinetic Energy 29 42 44 45 46 49 63 82 94 95 115 L Labels 13 14 16 21 24 26 27 31 39 71 78 79 81 89 99 102 108 113 115 116 119 120 Langmuir Blodgett films 20 Layer thickness calculation 20 30 37 81 84 85 86 117 Layer Thickness window 20 30 31 39 69 75 81 84 85 87 Layers 15 19 20 21 22 24 29 30 31 32 37 39 40 41 42 46 47 49 50 53 58 59 60 61 62 65 70 76 81 82 83 84 85 86 87 98 102 109 110 111 112 113 114 115 118 119 Layers on Cylinder model 54 97 Layers on Nanotube model 29 40 50 57 87 97 117 Layers on Plane model 37 38 39 51 97 99 112 119 Layers on Polyhedron model 31 55 87 97 98 118 Layers on Sphere model 39 52 97 117 119 Least square fitting 20 24 30 49 50 82 85 108 109 110 111 114 115 118 Library 6 7 9 13 14 23 26 27 63 64 70 72 77 83 89 107 109 110 111 117 118 119 120 124 Library Lookup 13 14 26 27 70 77 89 111 Limitations 120 Magic 23 33 67 117 Magic angle 23 Margins 104 Mass 16 48 80 Mass ratio 16 80 Material class 44 45 79 83 91 110 115 Me metal chemical state 8 21 32 78 111 Mean molecular weight 44 Menu access keys 107 Menus Edit menu 14 68 73 Edit Menu Notes window 73 File menu 66 73 101 File Menu Notes window 73 101 Format Menu Notes
37. 7 67 106 Print Options 17 67 103 Windows menu 71 Wizard 13 26 71 105 117 118 Word 9 17 34 68 74 X X category axis 16 24 27 78 81 99 XPS MultiQuant data files 9 10 11 12 17 20 33 34 35 36 37 38 39 40 66 84 106 110 XPS Reduced Data Exchange File 9 10 15 66 106 109 117 118 X ray flux 41 Y Y value axis 16 81 Z Zero and empty cells 14 78 Herr Prof Dr Rontgen 131
38. 77 90 108 E Ebel H 14 27 35 43 47 92 98 121 Edit menu 14 68 73 Edit Menu Notes window 73 Editing keys 107 Effective asymmetry parameter 43 Eject Page command 17 28 103 106 Elastic scattering 43 121 122 Elements 6 14 44 63 70 78 83 91 96 108 109 110 118 Elements window 13 14 21 27 32 37 49 66 69 70 115 Empty and zero cells 14 78 Empty row 14 68 ENTER key 20 30 85 107 Evans S 23 34 36 42 46 64 89 96 119 121 Example files 39 67 117 Excel 9 17 18 34 68 Excitation energy 26 64 88 119 126 Excitation source 13 23 24 26 42 43 63 64 88 89 92 114 115 Excitation analyser angle 13 23 42 64 114 Experiments 13 14 16 20 21 22 24 27 28 30 31 32 38 39 47 56 68 75 78 79 81 84 85 87 91 96 98 102 108 110 115 118 119 120 Explicit 22 49 79 91 96 Exponential 9 13 22 26 44 45 46 91 93 94 114 F FAT 64 93 File menu 66 73 101 File Menu Notes window 73 101 Fixed Analyser Transmission 64 93 Fixed Retarding Ratio 46 64 93 Flat surface 6 15 19 51 52 Font 17 28 74 104 Format Menu Notes window 74 FRR 46 64 93 G G 1 formula 45 91 Geometry correction factors 29 53 54 55 65 87 100 Graphical intensity comparison 20 81 86 Gries W H 22 25 29 45 79 91 110 115 117 118 122 H Hardware requirements 16 Help menu 72 74 Help Menu Notes window 74 Hess
39. Ag Au Alloy Weighted Multiline CuAgAu mqd A ternary Cu Ag Au alloy was prepared by grinding XPS spectra were measured after 10 s Ar ion sputtering which removed majority of carbonaceous contamination Intensity and all basic data including cross sections asymmetry parameters and transmission function were obtained from the literature 6 The measured Cu3p MgKa 2 line was superimposed with the Au4f MgKo34 X ray satellite thus the intensity of the Cu3p line was corrected by 10 of the Au4f intensity Sat corr There are significant differences between the concentrations calculated with different lines multiline approach method is set to None thus application of weighted average Ebel is advisable The concentrations mass calculated by the authors 6 and by XPS MultiQuant satellite corrected shown in the next table are in good agreement Cu Ag Au Chemical analysis 40 0 50 0 10 0 No satellite correction 39 4 50 4 10 2 Satellite correction 39 2 50 6 10 2 XPS MultiQuant Ebel 40 7 49 5 9 8 XPS MultiQuant Average 37 6 51 4 10 9 SiO contamination SiO2 contam mad XPS data were measured on a thermally oxidised Si wafer The sample was totally oxidised and no elemental silicon could be detected It was treated by low pressure oxygen plasma to remove residual carbon and reach the stoichiometric S1 O 1 2 ratio After measuring the clean state of the sample hydrocarbon contamination of increasing thickness wa
40. LF 13 10 characters for ASCII or by VT 11 character Manual Line Break for Word Paste Table Pastes the content of the clipboard to the active input window Elements Intensity IMFP amp Contamination or Model Data items must be separated by TAB and lines terminated by CR LF characters Clear Table Clears the whole content of the active input window Elements Intensity IMFP amp Contamination or Model or the results of the structured model calculations Cleared windows cannot be recovered 68 View Menu Window Help Elements i Intensity IMFFP amp Contamination v Results Chart Miodel Model Layout Parameters Motes Elements Displays or hides the Elements window Intensity Displays or hides the ntensity window Available only if elements are already entered into the Elements window IMFP amp Contamination Displays or hides the JMF P amp Contamination window Available only if elements are already entered into the Elements window Results Displays or hides the Composition or Layer Thickness windows Available only if elements and intensity data are already entered Chart Displays or hides the Chart window Available only if the Composition or the Layer Thickness window is displayed Model Displays or hides the Model window Available only if the selected model type is one of the structured ones the Model textbox in the General tab of the Parameters window Model Layout Displ
41. New Deletes all previously entered data from all windows and displays the Elements window Prints any pending page Settings of the parameters are unchanged except Title Open Invokes the Open Data dialog box for selecting previously saved XPS MultiQuant data files XPS MultiQuant template files or XPS Reduced Data Exchange files Open Example Invokes the Open Example Data dialog box for selecting example XPS MultiQuant data files XPS MultiQuant template files or XPS Reduced Data Exchange files The Notes window and 66 other subwindows are opened automatically and the result format is set as appropriate for the selected file Save Saves data in the current XPS MultiQuant data file shown in the status bar If data are not yet saved the Save Data As dialog box will be invoked Save As Invokes the Save Data As dialog box for entering name for a new XPS MultiQuant data file or XPS MultiQuant template file When an example file is saved it loses its magic and acts as an ordinary data file Save Defaults Saves the initial settings of the Parameters except Title Print and Print Options windows in the registry Print Invokes the Print window for selecting items to be printed forcing printing of the pending page and setting printing options If no printer is installed to the computer when the program is Started this item is not available Print Current Prints the active window to the printer If no printer i
42. V and a is the average monolayer thickness in nm calculated by equation 18 where M is the mean molecular weight and p is the density in gcm unit The numerical factor is derived from Avogadro s constant Tanuma Powell and Penn 9 10 proposed the following equations for calculating the IMFP as a function of electron kinetic energy and various material parameters Equations 19 25 are collectively known as TPP 2M formula Le ee 19 E5 LB n yE C E D E where F is the kinetic energy eV E is the free electron plasmon energy eV and B 0 10 0 944 Ef E2 0 069p 20 y 0 191 p gt 21 C 1 97 0 91 U 22 D 53 4 20 8 U 23 U N p M E 829 4 24 44 E 28 8 Nyp M 25 where p is the density g cm N is the number of the valence electrons per atom or molecule M is the molecular weight Eo is the bandgap energy eV Gries 9 11 developed the following G 1 equations 26 28 for the prediction of the IMFP 2 10k V Z E log E k 26 where V is the atomic volume cm mol Z isa parameter found empirically equal to Zz Z is the atomic number k and kz are parameters The terms V and Z are generalised to apply for compounds A Bg C Z pZ qZ rZz p q r 27 V pM qM rMeo plp q r 28 where p q r are the stoichiometric coefficients of elements 4 B C respectively M is the atomic weight p is the density
43. ab of the Parameters window the composition and other parameters of the layers must be described in the Model window Assign name to the layers and the bulk in the Name row Although the name stands for administrative purposes it indicates the presence of the layer for the program Fill out the molecular weight and density rows The Type row is displayed only in case of Island type models Enter I or L or double click to choose the sland or Layer type The next section is the atom location matrix it shows the stoichiometry of the layers 1 e the number of different atoms in a molecular unit The 0 element is the hydrogen which is obviously not part of the quantification but can be included for the molecular weight and IMFP calculations The last section is the IMFP matrix it shows the inelastic mean free path values for each layer and for each kinetic energy represented by the selected lines of the elements Use the measure unit selected in the JMFP and thickness measure box of the Model tab of the Parameters window Molecular weight and calculated IMFP data can be obtained automatically by the Tools Model commands When the automatic least square parameter fitting Autofit is used layer thickness values can be fixed kept constant during the fitting procedure or can be linked declared to be equal with an other neither fixed nor linked layer To change the linking of the layers double click the cells of the Link to row until the requir
44. able Type of the overlayers 1 Island 1 Layer 2 Island 1 Island 2 Island 3 Layer ITA CRA P7 f Li f Y Islands on a substrate Substrate is covered by a Islands on a substrate covered by a contaminant continuous layer and layer two layers islands Oxide Layer Model Me O a In the simplest cases when the layer and the bulk contain the same element in different chemical states the layer thickness d can be expressed analytically 23 24 A typical example is a metal surface covered with a single and uniform layer of its native oxide and the intensity of the photoelectron peaks of the metallic Ime and oxidic Jox chemical states of the same metal element can be resolved the intensity ratio can be written as Ime _ Nme Ame _ xP d hox cos 8 _ 62 lox Nox Aox 1 exp d A cos 8 61 where N is the number of atoms per unit volume is the inelastic mean free path d is the layer thickness and is the tilt angle from the surface normal Indexes me and ox refer to the bulk metal and layer oxide respectively Solving Equation 62 for the layer thickness it can be calculated directly d Ao cos In ine nes 63 OX OX me Parameters of the model should be defined similarly to the other structured models but here only one layer is permitted As the involved intensity originated from the same element practically at same binding energy no corrections are required for cross section tra
45. alculation Print the content of the active window Copy the content of the active window to the clipboard in ASCII form Search the library for element and line data Exit program Invoke What s This Help Display context sensitive help Editing Keys DELETE BACKSPACE ARROW keys ENTER TAB PAGE UP PAGE DOWN HOME END Delete the content of the current cell in a table Delete the last character of the current cell or a textbox Move the current cell in a table or the text cursor in a textbox Move the current cell right or to the beginning of the next row in a table Move the current cell right or to the beginning of the next row in a table Move the current cell up by one window Move the current cell down by one window Move the current cell to the beginning of the row Move the current cell to the end of the row Menu Access Keys Access keys allow the user to open a menu by pressing the ALT key and then type the underlined letter Once the menu is open the user can choose a control by pressing the letter the access key assigned to it Underlines are visible only when the menu is opened by the ALT key 107 Messages Angles of emission not entered The Angle dependent experiment set is selected but the angle of emission tilt angle values are not entered into the Tilt label set in the ntensity window Bad file name The specified filename is invalid Change or edit title Change or edit the title text Title can al
46. amination must be left empty when the automatic contamination correction Mohai is selected e The two chemical states of the main constituent element must be Ox oxide oxidic oxidised oxidized and Me met metal metallic when the Oxide Layer model is used Only the first two characters are significant Clicking some selected cells of the Element window assists entering data conveniently Double click the cells of the Line column to insert rotate the notation of the most frequently applied lines 1s 2p 3d 4d 4f while double clicking the cells of the State column enters the standard chemical state types Me Ox empty Intensity E Time min T Cr C Si 1 o 637624 669910 41953 2713533 2 10 467572 936964 20378 296118 3 20 436508 936100 21494 293938 4 30 429976 9389868 15150 302254 5 40 424544 955776 16565 290347 B 50 417772 942724 13359 292522 7 g g 10 Enter the integral photoelectron line intensity data into this table as supplied by the spectrum processing software XPS MultiQuant distinguishes the empty and zero cells so zero value can be used to emphasise the lack of an element Data of several experiments can be entered and calculated simultaneously The experiment may be an item in a Series e g ion bombardment heat treatment time dependence or simply a different but usually similar sample The number of the experiments is determined automatically thus empty lines are not allowed in t
47. an atomic weight of the material for the Seah Dench method when the same values are used for all experiments Use separate values Select this check box if separate material class density and mean atomic weight values are specified for each experiment in the JMFP amp Contamination window for the Explicit Jablonski Seah Dench or Gries methods Apply this feature when the experiments were performed on different materials or the samples were changed during measurements or treatments Calculate mean atomic weight Select this check box to calculate the mean atomic weight values automatically in a two step iteration for the Seah Dench method Show Displays the table of the actually applied IMFP values or numbers proportional to IMFP as illustrated in the next figure 91 Time min i I 10 20 30 40 50 LO Oo m1 Oo oO ee poo a a aot Angular Tab Contannaion Medes abe Method Rellmari Excitation analyser 650 angle Frint Cancel Apply OF Method Select the applied angular correction method None no angular correction Reilman method of Reilman Reilman Ebel method of Reilman with correction for elastic scattering Excitation analyser angle Set the angle between the excitation source and the axis of the analyser in degrees 92 Transmission Tab Contamination Model Labels General Cross section OMP Angular f Transmission Type Fie File type Exponential
48. ange files name icon and associated program HKEY CURRENT USER Software VB and VBA Program Settings XMQ Defaults HKEY CURRENT USER Software VB and VBA Program Settings XMQ In1 HKEY CLASSES ROOT mqd HKEY CLASSES ROOT MOQDfile HKEY CLASSES ROOT mtr HKEY CLASSES ROOT MTRYfile HKEY CLASSES ROOT mat HKEY CLASSES ROOT MQTrfile HKEY CLASSES ROOT mqx HKEY CLASSES ROOT MOQXfile Data template and exchange files are associated with the XPS MultiQuant application while transmission files with Notepad Hardware Requirements There is no special requirement any computer with x86 compatible processor is satisfactory If the operating system can run with tolerable speed XPS MultiQuant will run as well The program occupies 2 8 Mbytes of hard disk space depending on components already installed Printer is recommended Computers in the future may weigh no more than 1 5 tons Popular Mechanics 1949 640K ought to be enough for anybody Bill Gates 1981 10 Miscellaneous Remarks In Windows NT Windows 2000 Professional Windows XP Professional Windows Vista and Windows 7 operating systems user may have to own administrative privileges to install some system components The name of the Windows and Windows System folders where the shared components are located may be slightly different e g WinNT and WinNT System32 in the various versions of the operating system In 64 bit operating systems the 32 bit applicat
49. ange the material class of the layers double click the appropriate row or enter the initial letter e 1 p Providing of the bandgap energy and the number of the valence electrons are required by the Tanuma Powell Penn method only The number of the valence electrons can be calculated automatically by the Tools Model Calculate Valence Electrons command 83 Layer Thickness Name Layer Layer z al LH Sie 114 10 83 1 84 2 B 3 95 16 51 U0 42 0 39 4 D 5 06 1 56 T E hae 19 16 6 IF 6 59 3 75 G 12 r4 2 5 A 4 10 The results of the layer structure calculations are summarised in the Layer Thickness window invoked by the View Results command Layer thickness is shown in the same unit as selected in the Model window The columns have double header lines showing both the type and number and also name of the layers The Coverage column is displayed only when one of the sland type model is selected Since layer thickness values are not calculated automatically the table is empty when first displayed The calculated layer thickness values unlike other results are stored in the XPS MultiQuant data files To invoke the layer calculation double click the sequence number of the required experiment To select an experiment for displaying in the Model Layout window click the sequence number When an angle dependent experiment set is calculated results will be appear only in the first row indicating that all of the experi
50. arbon e g carbonate or carbide types can be separated by decomposition from the hydrocarbon type contamination use different State settings Such correction method on the other hand cannot be applied to samples containing hydrocarbon type constituents like polymers Sample Correction c factor Na Cl NaCl None 0 1 0 0 96 clean Evans 14 3 1 0 0 98 Mohai s 0 1 0 0 96 NaCl None 0 1 0 0 90 highly Evans 14 3 1 0 0 92 contaminated Mohai s 64 6 1 0 1 01 Sample Correction c factor Si O S105 None 0 1 0 2 01 clean Evans 14 3 1 0 2295 Mohai s 4 3 1 0 2 08 S105 None 0 1 0 1 31 highly Evans 14 3 1 0 1 46 contaminated Mohai s 50 6 1 0 1 94 23 Angle of Emission If you perform a series of angle dependent tilt experiments where the angle of emission take off angle the angle between the sample surface normal and the analyser axis is other than zero 1 e not perpendicular select the Tilt label set and enter the angle values there In the case of the Homogeneous model it can be applied only as X axis set However if your data are depending on the tilt angle it clearly proves that the sample is not homogeneous When one of the planar type structured models is applied the angle values are taken into account in the equations marked by shown in chapter Applied Methods In case of curved surfaces only the perpendicular view is permitted thus the angle values are not used When you select the Angle depend
51. ard than in the selected range the unused portion of the clipboard is ignored The structure of the clipboard text is described at the Copy Table command Cut Cells The content of the active cell or the selected range is copied to the clipboard then the selected region is cleared When the entire content of two or more lines of the Elements or Intensity windows are cleared by the Cut Cells command the content of the underlying lines may be lost because of the automatic counting of elements and experiments Copy Cells The content of the active cell or the selected range is copied to the clipboard The selected region remains unchanged This command is also available in the Compositionand and Layer Thickness windows Paste Cells The content of the clipboard is pasted to the active cell or the selected range The selected range 1s overwritten Available only when the clipboard contains text data Alphabetic text pasted into the numeric cells is treated as zero Undo Paste Undoes the last Paste Cells command This command is available only in the same window where the last Paste Cells was executed There is only one level of undo Pop up Menu Chart window Copy Chart Colours This pop up menu activated by a right mouse click is available in the Chart window Copy Chart Copies the content of the Chart window to the clipboard in Windows Metafile WMF format Colours Switches on or off the colours of the chart 75 Pop
52. are enabled only when the previous step was completed successfully but of course the wizard cannot prevent from all potential errors When the Always on top check box is selected the wizard s window is kept on the top of all other windows including other applications This window is not restricted to the main window of the program it can be positioned anywhere on the screen The wizard can be switched off at any time by the Tools Data Wizard command or by its close button Start wizard automatically Select this check box to start Data Wizard automatically when XPS MultiQuant is started Always on top Select this check box to keep the wizard s window on the top of all other windows 105 Open Save As oe gt Program Files XMOQ Samples Search Samples P Organize New folder wn Name Type Size Date modified D Al Lavers mad XPS MultiQuant Data SKB 06 04 11 00 17 D l Oxide mad XPS MultiQuant Data 2KB 06 04 11 00 18 Cer met mad PS MultiQuant Data SKB 06 04 11 00 19 1 Cer met mgt XPS MultiQuant Template KB 06 04 11 00 23 f Cer met mgx XPS Reduced Data Exchange 1KB 10 08 05 16 58 1 Contact mad XPS MultiQuant Data 6B 06 04 11 00 19 1 CuAqAaU mgd XFS MultiQuant Data SEB 06 04 11 00 20 f SiN powder mgd XPS MultiQuant Data SEB 06 04 11 00 20 File name AILXPS MultiQuant Files rmngd Open e Cancel This is a standard Windows dialog box for opening and saving XPS MultiQuant
53. ary Separate data set are available for Mg Ka and Al Ka excitation sources Number of Valence Electrons The numbers of valence electrons of the elements recommended by Powell et al for the TPP 2 formula are extracted from the literature 9 The contributions of the 4f electrons of the rare earth elements are excluded as suggested 9 64 Geometry Correction Factors 0 6 0 5 Se Q A z J ja J c 04 pe a D 0 3 9 gt 09 Sphere 5 O Sphere single row Q 0 1 amp Cylinder 0 0 I I I I I 0 10 20 30 40 50 60 70 80 90 Middle angle of segments The geometry correction factors for calculating photoelectron intensity values from layer thickness on curved surfaces were calculated by Vars nyi et al 17 18 for sphere and by Mohai for cylinder 18 These factors are based on pure geometry considerations An atom says to his friend Man I think I ve lost an electron The friend says Are you sure He answers I m positive 3 65 Program References Menu Commands Use menu commands to control XPS MultiQuant Click the menus or press ALT and type the access key underlined or press the shortcut key to perform some commands directly File Menu File Window Help o Ctrl t Ctrl 0 Open Example Save Ctrl 3 Save BS sawe Defaults Print Print Current Ctrl P Exit
54. atio was calculated for assumed combinations Cr203 SiO Cr203 Si and Crt SiO The Oxygen balance values of the different settings are depicted on the figure as a function of the bombardment time The chart revealed that the top surface is totally oxidised 1 e Oobs Oca 1 for the assumed Cr203 S102 compounds After 10 min bombardment the top layer is removed and the former composition gives unrealistic oxygen deficiency The new composition of the layer is close to either of the Cr203 S1 or Cr Si0 or also CrO S1 supposed structures Further bombardment does not change the composition Chemical shifts of the photoelectron lines will determine the correct chemical structure but this method can reduce the choice discard unrealistic combinations and by this backs the peak decomposition procedure To calculate the Oxygen balance for the above assumed compositions in three separate runs set the Valence and Oxygens columns in the Elements window as follows Cr Valence Cr Oxygens Si Valence Si Oxygens CroO3 z5 S10 gt 3 3 4 2 Cr20 Si 3 3 0 0 Cr SiO 0 0 2 l Oxidised Si Si wafer mad Spectra were measured on a silicon wafer covered with a native oxide and a hydrocarbon contaminant layers The Layers on Plane model was applied to calculate the thickness of the layers The composition of the layers was assumed to be SiO and CH For checking purposes the layer thickness values were also calculated after the decomposition of the Si2p lin
55. ause the layer thickness values are not calculated automatically For the same reason the calculated thickness values are stored in XPS MultiQuant data files To calculate the layer thickness double click the sequence number of the selected experiment The Layer Calculation window is displayed Select a basis element for the relative intensity comparison by double clicking the element symbol in the upper panel Estimate and enter the thickness of each layer to the small table below and press ENTER When the last number is entered the relative intensity is calculated and displayed The Diff column shows the percentage difference between the calculated and measured intensity while the Qsum row shows the sum of the squares of the differences The Chart window let you compare the intensity values graphically see chapter Layer Calculation You can enter the next estimation immediately intensity values are recalculated and displayed The results of the previous calculations the last two ones are also displayed for comparison If you do not enter thickness to a cell but press ENTER the previous value is retained Vary the thickness of the layers until calculated intensity values are the closest to the measured ones 1 e perform a manual least square fitting or press the Auwtofit button to calculate the parameters automatically Then press the OK button or select the next or previous experiment by the small arrow buttons The results of the calculatio
56. ayer thickness and the unchanged radius of the tube Multiline approach Select the applied multiline calculation method for the Homogeneous model None no multiline calculation Average simple average of raw data for all lines of each element and chemical state Ebel weighted average of raw data for all lines of each element and chemical state Sphere or cylinder radius When the radius of the sphere or cylinder is set to zero it means that the radius of the curved surfaces is much larger 1000 times or more than the layer thickness In this case the simplified formula equation 56 is used for calculations In other cases enter the actual radius in the same unit used for the layer thickness and IMFP The outer radius of the nanotubes must always be specified Tube inner radius Enter the inner radius of the nanotubes In case nanofibres or nanowires where is no hole enter zero Multilayers Set the number of repetition of the layer structures defined in the Model window Fit coverage automatically When this check box is selected the coverage of the s and type models is refined during the autofit procedure Angle dependent experiment set When this check box is selected all experiments recorded at various take off angles are linked and the thickness of the layers calculated together This feature is available for the Layers on Plain and Islands on Plain models Edit Invokes the Polyhedron Editor window Available o
57. ays or hides the Model Layout window 69 Parameters Displays the Parameters window Notes Displays the Notes window Tools Menu Tar File Edit View Tools Window Help Library Lookup Ctrl L Model b Test Model Simulation Mark Unused IMIFP s Create Depth scale Calculate Molecular Weight ata S P Calculate Valence Electrons Calculate IMIFPs Library Lookup Searches XPS MultiQuant s library for element and photoelectron line data for the elements given in the Elements window according to the settings in the Parameters window Library must be enabled Search can be performed either for the whole content of the window or for selected lines only To select lines click the line number of the first line then drag or SHIFT click the last one This command works only when invoked from the Elements window Model gt This menu contains tools which help and automate filling of the structured model data These commands work only when invoked from the Model window Test Model Performs the model data consistency tests and displays the results and possible error messages in the Model Summary window These tests are normally performed only at closing of the Model window Mark Unused IMFPs Marks the positions in the IMFP matrix of the Model window which are unnecessary for calculating of the specified layer structure Calculate Molecular Weight Calculates and fills the molecular weight values o
58. blonski K Hirokawa Quantitative XPS Multiline Approach J Electron Spectrosc Relat Phenom 40 1986 241 7 A Jablonski Universal Energy Dependence of the Inelastic Mean Free Path Surf Interface Anal 20 1993 317 8 M P Seah W A Dench Quantitative Electron Spectroscopy of Surfaces A Standard Data Base for Electron Inelastic Mean Free Path in Solids Surf Interface Anal 1 1979 2 9 C J Powell A Jablonski NIST Electron Inelastic Mean Free Path Database Version 1 1 National Institute of Standards and Technology Gaithersburg MD 2000 121 S Tanuma C J Powell D R Penn Calculations of Electron Inelastic Mean Free Paths 5 Data for 14 Organic Compounds Over the 50 2000 eV Range Surf Interface Anal 21 1994 165 W H Gries A Universal Predictive Equation for the Inelastic Mean Free Pathlengths of X Ray Photoelectrons and Auger Electrons Surf Interface Anal 24 1996 38 P J Cumpson M P Seah Elastic Scattering Correction in AES and XPS II Estimating Attenuation Lengths and Conditions Required for their Valid Use on Overlayer Substrate Experiments Surf Interface Anal 25 1997 430 P J Cumpson M P Seah S J Spencer Calibration of Auger and X ray Photoelectron Spectrometers for Valid Analytical Measurements Spectroscopy Europe 10 1998 2 http www npl co uk nanoscience surface nanoanalysis products and services R Hesse P Streubel R Szargan Improve
59. bration System 13 software The coefficients of the UNIFIT type combined function ao aa bi b2 of equation 34 must be entered in one line Parameters of this kind of function can be calculated by the Unifit for Windows 14 program The latter two function types are valid for the whole energy scale thus no energy ranges are presented 1n the file 94 At first glance the zero order polynomial and the tabulated functions seem to be identical However in the first case a constant transmission is used in each energy range step like function while in the second case transmission is calculated by linear interpolation within the ranges The differences are illustrated in the next figure 70 H Polynomial POLY 0 0 60 200 40 Tabulated TAB 0 200 60 TAB 50 em POLY 0 40 400 24 600 800 1000 400 600 800 1000 30 Transmission 20 10 0 200 400 600 800 1000 1200 Kinetic energy eV Transmission files must be carefully checked before use Although the files are thoroughly tested some kinds of errors cannot be detected and may produce unexpected results e g numbers are truncated at the accidentally entered non numeric characters Examples Example 1 Example 2 EXP POLY 3 100 100 500 500 1500 1500 Example 3 NPL 4 23 40 50 G0 kg l3 L9 Moy 22 In the first and second examples the coefficient set of the fi
60. calculated knowledge of the actual IMFP values is essential For these types of calculations always the explicit values are used All other selectable methods 8 11 are applied to compute the IMFP values prior the layer thickness calculation Although there is only one location to set the IMFP correction method 1 e the JMF P tab of the Parameters window two different method names one for the homogeneous and one for the structured models are maintained Only the methods associated with the model can be selected The following table enumerates the selectable methods for each model types and also shows the source the names of the windows in the program of the IMFP data or the parameters to calculate them Location of Location of parameters a a IMFP data to calculate IMFP Homogeneous model None Explicit IMFP amp Contamination Exponential Parameters Jablonski IMFP amp Contamination Seah Dench IMFP amp Contamination Gries IMFP amp Contamination Structured models Explicit Model Seah Dench Model IMFP amp Contamination Tanuma Powell Penn Model IMFP amp Contamination Gries Model IMFP amp Contamination Cumpson Seah AL Model Model When the same parameters are used for all experiments values can be set in IMFP tab of Parameters window as well 22 Miscellaneous Remarks Mixing of Methods and Data Every term of the sensitivity factors can be controlled independently h
61. class or the number of the valence electrons are not set the density is greater than 22 5 etc The error is reported only if the parameter is necessary for the selected method e g bandgap energy is required only by the Tanuma Powell Penn method Sputter rate not set The Tools Create Depth Scale command was selected but the sputter rate on the Labels tab of the Parameters window is not set or zero Enter sputter rate first Subscript out of range occurred at fitting of parameters N Check model and refine initial data A reference was made to a non existing array element during the least square fitting of model parameters Check model definition in the Model window and the Model tab of the Parameters window Subscript out of range occurred at model calculation N A reference was made to a non existing array element during calculation of intensity of structured models The symbol line cannot be excited by the selected source Line energy changed to give positive kinetic energy The binding energy of the selected line is higher than the energy of the excitation source The specified energy of the line was changed to excitation energy minus one to give positive kinetic energy value This line cannot be present in the spectra thus delete it in the Elements window The cosine of the angle between the function values and the columns of the Jacobian matrix is at tolerance The cosine of the angle between the solution vector and any column
62. correction factors are predefined here the factors should be defined by the user The effective thickness of the layers is varying from facet to facet positioned at different angles Thus the intensity data originating from the various facets of the sample are weighted by a geometry correction factor accounting for the projected areas Similarly to the other structured models the size of the surface features must be greater than thickness of the layers 55 The surface should be inspected by naked eye or by microscope and the tilt angles of the facets together with their corresponding relative area should be measured e g by optical methods goniometer or image analysis etc or estimated The above example shows a grooved surface with roof shaped features The projected areas could be derived from the top view while the tilt angles from the side view The relative projected area data to be included into the model are shown in the next table Y n When angle dependent experiments are performed the model geometry must be redefined as the effect of tilt on the different features are unpredictable in general It is strongly depending on relation of tilt direction with the position of facets on the self shading effects of the features etc Projected area at sample tilt Facet tilt angle 0 60 0 33 3 66 6 30 16 7 16 7 60 50 0 16 7 As shown in the above table the relationship between the projec
63. d Accuracy of Quantitative XPS Analysis Using Predetermined Spectrometer Transmission Functions with UNIFIT 2004 Surf Interface Anal 37 2005 589 http unifit software de M Mohai I Bertott Correction for Surface Contaminations in XPS A Practical Approach in ECASTA 95 Eds H J Mathieu B Reihl D Briggs John Willey amp Sons Chichester New York Brisbane Toronto Singapore 1995 p 675 B S Garbow K E Hillstrom J J More MINPACK Project Argonne National Laboratory 1980 http gams nist gov serve cgi Module MINPACK LMDIF 8379 G Vars nyi G Mink K R e M Mohai Consideration of Two dimensional Surface Roughnesses in Quantitative XPS Analysis Periodica Polytechnica 31 1987 3 M Mohai I Bert ti Calculation of Overlayer Thickness on Curved Surfaces Based on XPS Intensities Surf Interface Anal 36 2004 805 M Mohai Calculation of Layer Thickness on Rough Surfaces by Polyhedral Model Surf Interface Anal 40 2008 710 122 20 21 22 29 24 25 26 2I 28 29 30 31 M Mohai I Bert ti Calculation of Layer Thickness on Nanotube Surfaces from XPS Intensity Data Surf Interface Anal to be published H Kanzow P Bernier A Ding Lower limit for single wall carbon nanotube diameters from hydrocarbons and fullerenes Appl Phys A 74 2002 411 T Vodenitcharova L C Zhang Effective wall thickness of a single walled carbon nanotube
64. data files template files transmission files or XPS Reduced Data Exchange files The default file extension is mqd mqt mtr and mqx for the data template transmission and exchange files respectively Select or type the proper file name or navigate in the folders as usual in Windows The common Windows pop up menu right click is also available for file deleting renaming etc Files on mapped network drives can be opened only with writing permission This window may look different in the various versions of the operating system Status Bar SEN powder C Program Files sMO Samples SiN powdermad sis NUM The status bar located at the bottom of the main window shows some important information of the program It is divided into four panels The panels show e The title of the calculation To change or edit the title double click the panel or use the General tab of the Parameters window e The name and the path of the current data file If the path is long and the filename cannot be read double click to alter the alignment of the text e The presence of a pending unfinished page To print the pending page double click the icon or press the Eject Page button in the Print window e The status of the NUMLOCK key 106 Keyboard Commands Shortcut Keys CTRL N CTRL O CTRL S CTRL P CTRL C CTRL L ALT F4 F1 F2 Reset XPS MultiQuant and start new calculation Open an XPS MultiQuant data file Save current c
65. deleted Oxygen Balance column is displayed etc However when the user resizes any window manually it will keep its new size and will not be resized automatically until it is closed and reopened again Elements Symboalj Line State B E Cross Asymm Atomic w Yalence Osygens a 1 0 1s 531 0 U b24 2 000 16 00 2 0 2 Cr 2p 574 0 2 340 1 459 AOU 3 3 P 1s 205 0 0 225 2 000 12 01 4 0 475 2p 99 0 0 230 1 106 250 09 4 2 5 6 H 4 10 Enter element symbols and photoelectron line assignations of the elements required for the calculations Use the 2p 3d 4f etc notation for the doublet lines and the 2p3 3d5 4f7 etc for the 2p3 2 3ds 2 4f7 2 components respectively Capitalisation errors of the element symbols are corrected automatically Use the State column to distinguish the different chemical states of the same element Data can be extracted from the library by the Tools Library Lookup command or can be entered manually Data taken from the library can also be overwritten The Valence column is the valence of the element at the given chemical state and the Oxygens column is the number of oxygen atoms in a mol of such oxide When the window is left or closed the data in the table are checked and a message may be displayed about possible errors The number of elements is determined automatically thus empty lines are not allowed in the table 77 Special cases of the State entries e The Cls line of carbon cont
66. dependent elements Model error s The model system is ill defined Supply coverage data from independent measurements or specify one more element in the islands None of the islands has at least two independent elements Automatic fitting of the coverage is not possible unless one more element is specified in one of the islands Model error s Thickness of the carbon nanotube wall seems to be too small The absolute wall thickness of the carbon nanotube is smaller than the minimal value specified in the literature Model structure not defined One of the structured model types is selected but no layer structure is defined in the Model window Select the Homogeneous model or define the layer structure No element specified Some features of the program cannot be accessed before the elements are specified Enter all elements first No independent parameter to fit All layer thickness and coverage parameters are fixed or linked Check the Link to line in the Model window and the Model tab in the Parameters window No transmission file specified The transmission type was set to File in the Transmission tab of the Parameters window but no file name was given in the Filename box Number of parameters greater than expected File may be corrupted The number of parameters in the data file is greater than the program expects The file is invalid or damaged Numeric label set is not empty Do you want to overwrite The Tools Create Depth Scal
67. does not describe properly the examined system When the Modified tube layer variant of the Layers on Nanotube model is used the above iterations are nested into an external cycle which iterates the wall thickness of nanotube As this model can be applied only for one layer the convergence is usually not slower than in simple cases There are some other characteristics to assist defining more complex models If there is some a priori knowledge on the relation of the various layers thickness of the different layers may be declared to be equal or can be kept constant When a set of layers is repeated in sequence on the sample it is enough to define one repeating unit and to set the number of the repetitions Elements or layers can be excluded from the automatic fit calculation if necessary The fitting routine is not restricted by the physical meaning of the parameters When any of the results seems to be unrealistic e g a negative or too large layer thickness a warning message 1s displayed 50 Layers on Plane Model 3 gt m kK Ss d d gt N a S2 o B The photoelectron intensity emitted from a flat infinitely thick sample covered with overlayers of d dz thickness can be calculated by equations similar to 1 4 For example intensity of elements i j and k from a flat bulk sample B covered by two overlayers S and S2 are expressed by d gt Nk exp 28 cos dx 0 53 N A c
68. e R 122 Hexagonal lattice 53 Homogeneous model 13 19 22 24 25 26 29 39 41 87 89 97 98 113 117 Hydrocarbon contamination 14 23 35 37 38 IMFP 6 13 14 15 21 22 25 26 29 34 41 42 44 45 46 47 49 51 60 62 63 64 68 69 70 71 74 79 82 83 88 89 90 91 96 98 110 112 113 114 115 117 118 IMFP amp Contamination window 14 69 71 79 83 91 96 IMFP matrix 70 71 82 89 Inelastic Mean Free Path 6 13 14 15 21 22 25 26 29 34 41 42 44 45 46 47 49 51 60 62 63 64 68 69 70 71 74 79 82 83 88 89 90 91 96 98 110 112 113 114 115 117 118 Infinitely thick homogeneous sample 6 42 97 Inorganic materials 44 45 91 110 Insert Element 14 28 68 Experiment 14 28 68 Installed files 8 Installing 7 8 11 Instrument factor 41 Intensity 6 14 15 16 19 20 21 24 27 28 30 32 34 35 37 38 39 40 41 42 47 49 51 52 53 55 57 60 61 62 63 68 69 71 74 75 78 81 84 85 86 94 96 99 102 108 109 110 113 114 115 116 117 119 123 124 Intensity comparison 20 81 86 Intensity Simulation 21 32 39 71 102 110 117 Intensity Simulation window 21 32 39 71 102 110 Intensity window 14 16 21 28 39 69 75 99 102 108 110 116 117 Island type models 49 82 85 87 98 Islands on Cylinder model 60 118 Islands on Plane model 60 99 119 Islands on Polyhedron model 60 Islands on Sphere model 60
69. e Cancel button General Tab Cross section IMFF Angular Transmission j Contamination Model Labels General Title Osidised Si i Excitation MoE a Energy 1255 6 ey Measurement unit nm Convert units be Enable library lookup Pririt Cancel Apply Uk Title Identify the whole calculation set If it is not entered here it is asked before the data file is saved Title can also be edited by double clicking the status bar Excitation Select the excitation source energy It can be Mg Ka Al Ka or Other When the latter is selected user must specify the source energy Energy Set the energy of the excitation source when the Excitation is set to Other Measurement unit Select the measurement unit of the inelastic mean free path thickness values and sphere cylinder or nanotube radius ngstr m or nanometer 88 Convert units Select this check box to convert the already entered IMFP and thickness values when changing the measure unit A to nm or nm to A The converted items are IMFP data of the Homogeneous model IMFP matrix of the structured models results of the structured model calculations radius of the sphere cylinder or nanotube sputter rate temporary depth scale The permanent depth scale stored in the Other numeric label set however is not converted automatically To convert it repeat the Tools Create Depth Scale command Enable library lookup Unselect this check box to prevent the quan
70. e command was selected but the target label set stores previously entered data Press OK to overwrite Overflow during calculating intensity ratio Layer N seems to be too thick There is enormous difference between the intensity values of one of the calculated and the basic elements It is usually caused by a large layer thickness or an extreme measured intensity value possibly miswritten The second sentence is displayed only when the thickness of the concerned layer is at least 25 times larger than the largest IMFP value Overflow during calculation Check window content Overflow was occurred during calculations One of the input data 1s larger than can be stored in the variables of the program larger than 3 4 10 Check the contents of the input windows 113 Overflow Too large number in transmission file One of the coefficients of the transmission function is larger than can be stored in the corresponding variable Edit the transmission file Overflow occurred at fitting of parameters N Check model and refine initial data Overflow was occurred during least square fitting of the model parameters It may be caused by wrong initial data or that the model is not properly describe the measured data Overflow occurred at model calculation N Overflow was occurred during calculation of intensity of structured models Parameter error s Invalid transmission exponent The exponent of the Exponential transmission correction method i
71. e dependent experiment set is selected the results are displayed only in the first row of the Layer Thickness window Defining Polyhedral Surface Geometry 1 On the View menu click Parameters 2 Click the Model tab Select the Layers on Polyhedron model 3 Click the Edit button The Polyhedron Editor window appears 4 Select the required angles of polyhedron facets by the slider and enter the projected area for each type as percentage value 5 Click the OK button 31 Notes e To check or set the 100 sum of the area values click the Normalise button e To remove previously entered data click the Clear button Setting up Oxide Layer Model 1 On the View menu click Parameters Click the Model tab Select the Oxide Layer model Click the OK button 2 Inthe Elements window type the chemical symbol and line notation e g Si 2p of the main constituent element of the bulk and the layer Copy the element to the next row 4 Type Me and Ox into the State column or double click the cells of the State column to denote the different chemical sates of the same element metal and oxide respectively Enter intensity data as described previously 6 Set up structured model as described previously Define one layer only On the View menu click Results Notes e Results are calculated and displayed automatically Setting up Intensity Simulation 1 Setup a structured model as described previously 2
72. e into components representing the elemental and oxidised chemical states Both calculations produced realistic and comparable results Calculation method d sio nm d cH nm from total intensity 1 6 22 from decomposed S12p intensity 1 6 1 9 For details about how to perform of the calculations see chapters Application of Structured Models and Layer Calculation Al O3 on Aluminium AI Layers mqd Al Oxide mqd XPS data recorded at 0 and 60 degrees take off angles on rolled aluminium foil covered with oxide layer and carbonaceous contamination Thickness of the alumina layer was calculated both by the Layer on Plane model with various settings with and without oxygen as angle dependent set and by the Oxide Layer model 37 To calculate the experiments together select the Angle dependent experiment set check box in the Model tab of the Parameters window To include and exclude oxygen double click the O row of the Omit column in the Model window Tilt angle d cu A d ALO A Layers on Plane 0 14 29 67 01 with oxygen 60 14 21 57 54 ARXPS 14 27 67 02 Layers on Plane 0 17 53 61 95 without oxygen 60 15 63 55 83 ARXPS 16 41 63 26 Oxide Layer 0 61 95 60 7 55 83 The results of the calculations are slightly different due to the oxygen surplus OH groups and the low intensity of metallic Al at 60 angle The thickness values calculated by the Oxide Layer model are the same as calculated by the Lay
73. e of the sample can be flat e g thin layers coatings etc spherical coated powder particles e g paints fillers supported catalysts cylindrical including nanotubes e g coated fibres for composites or rough modelled by polyhedrons e g grooved knurled surface surface covered by individual crystallites The program can handle as many as five layers it is usually more than enough for the practice First enter the elements and intensity data as usual and select the model type in the Model tab LE Islands on Plane Plane i 1 Layers on Cylinder Islands on Cylinder Layers on Nanotube SANN vy ag oa TS hh tS Sta Ve Ve Layers on Polyhedron Islands on Polyhedron of the Parameters window Invoke the Model window by the View Model command available only when the model type is not Homogeneous Give a descriptive name for each layer and the bulk material You declare the presence of a layer by naming it thus the name is obligatory Fill out the table according to chapter Model in Program References 19 Temporarily switch to Homogeneous model and study the overall composition of the underlying layers this helps to estimate the layer thickness then switch back to the required structured model Close the Model window and open the Layer Thickness The Layer Thickness window shows the thickness of the overlayers for the experiments The table is empty when first invoked bec
74. ed notice is visible Elements can also be omitted from the automatic calculation To omit an element double click the Omit row in the atom location matrix an X appears 82 Model Summary Model type AN Elements Layers Islands Number of equations Number of necessary elements within lard The model systern 1 ill defined Supply coverage data from independent measurements or specity one more element in the islands The Model Summary window invoked by the Tools Model Test Model command shows a brief summary and the results of the consistency tests of the data describing the current model numeric range of data consistency of composition and IMFP values number of equations validity of links etc These tests are normally performed only at closing the Model window thus by the above command the model can be checked as necessary without closing and re opening the window IMFP amp Contamination of Structured Models Polymer Inorganic Folymer 432 56 319 24 432 36 0 780 3 250 0 780 Bandgap energy 6 000 6 000 6 000 Valence electrons 144 44 144 The parameters of the IMFP calculations for the structured models are taken from the IMFP amp Contamination window The molecular weight and density data are the same as in the Model window and can be change in either of them If Element is selected as material class for a layer when its density row is empty the value is automatically extracted from the library To ch
75. ed to remove most of the contamination These results were calculated using theoretical cross sections and IMFP approach Data of this sample are used to illustrate of pasting XPS MultiQuant data into Microsoft Word documents see the SteelDocument doc file NaCl Scaling of Na1s Cross Section NaCl scaling mqd Spectra were measured on a freshly cleaved NaCl single crystal It was practically free from contamination with a low level of C and O impurities only This example illustrates of using of the scaling feature The cross section data set of Evans does not contain data for the Nals line However switching on scaling rough results can be obtained Compare the two scaling methods to the results calculated from the Na2s line 34 NaCl Simple Multiline NaCl multiline mqd Spectra were measured on a freshly cleaved NaCl single crystal with low level of carbon and without oxygen impurities The concentration of sodium is calculated using either the Is or 2s line or both lines In the latter case the average of the raw results is calculated for all lines of matching elements and chemical states The intensity and basic data are reliable for both sodium lines thus almost no difference can be observed when the multiline approach method is changed from Average to Ebel as shown in the next table atomic ratio Na Cl C Nals only 0 95 1 00 0 04 Na2s only 1 00 1 00 0 04 Both Average 0 97 1 00 0 04 Both Ebel 0 97 1 00 0 04 Cu
76. ent experiment set check box in the Model tab of the Parameters window all of the experiments recorded at various angles are linked and the calculation of the layer thickness performed together Automatic and Manual Fitting of Layer Thickness When you perform Autofit during layer thickness calculation you may encounter that the Qsum value becomes larger than previously reached manually This can be caused by several factors and does not mean that the fit become worse e The Autofit procedure is more complex not simply the least squares are minimised e The actual numeric value of Qsum 1s depending on selection of the basis element It is not necessarily the same at the manual and the automatic calculation e At manual calculation Qsum contains the contribution of all elements including the omitted ones During automatic calculation omitted elements are neglected The fitting procedure knows the mathematics only 1 e not restricted by any physical consideration results should be always revised by the experienced surface analyst Calculation of Coverage Be careful when the coverage is calculated automatically in case of island type models Small changes in coverage may cause significant changes in the calculated intensity The fitting procedure may be frequently trapped in local minima Always try to continue the calculation click Autofit again until there is no change in the results Repeat the calculation with diffe
77. ent without further warnings Invalid material class at IMFP calculation The material class Element Inorganic or Polymer is not set or unknown at IMFP calculation by Seah Dench or Gries methods Invalid procedure call e g square root of negative number occurred at fitting of parameters N Check model and refine initial data The argument of the function was out of the expected range e g square root of a negative number It may happen when the radius of the spheres or cylinders given in the Model tab of the Parameters window are not zero i e structures are relatively small and during the iterations of the least square fitting one of the layer thickness values became negative This error may also indicate that the model does not describe properly the measured data To solve the problem set the radius to zero try to fit parameters reset the radius to its correct value and fit parameters again 110 Invalid procedure call e g square root of negative number occurred at model calculation N The argument of the function was out of the expected range e g square root of a negative number Invalid transmission data No transmission used Some of the coefficients in the transmission file are too large to calculate the transmission function or some of the calculated factors are negative or zero Edit the transmission file to fix the error Layer thickness must be non negative Negative numbers cannot be entered as layer th
78. er and rows of a table are kept together take it into account when selecting the margin and font sizes Large tables which cannot be printed to one page are tiled A sample page of XPS MultiQuant output is illustrated above For printing the content of Notes and Parameters use the Print button of these windows Exporting Results Although the printed output of XPS MultiQuant is satisfactory in most of the cases you may want to insert the results into your documents The content of any window except Parameters and Chart can be copied to the clipboard by the Edit Copy Table command and pasted into any Windows application Two subcommands are available apply the Edit Copy Table ASCII command to paste data into text files Excel worksheets etc and the Edit Copy Table MS Word to paste into Word documents and create Word tables Only whole tables with column headings can be exported If you want to exchange data between two instances of XPS MultiQuant press SHIFT key and use the Edit Copy Table ASCII and Edit Paste Table commands to copy tables without headings To copy text from or paste into the Notes window use the commands of the pop up menu right click The graphics of the Chart and Model Layout windows can also be transferred to other applications by the Copy command of the pop up menu of these windows 17 XPS MultiQuant 6 10 Nitrocarburised steel File Steel mqd 14 January 2011 1999 2011 M Mohai Parame
79. ers Model error s Some parameters out of the expected range Some of the layer data is out of the expected range e g molecular weight is less than 1 or density is greater than 22 5 etc Model error s The composition of bulk not specified The stoichiometric coefficients of the bulk material in the atom location matrix of the Model window are not set or all are zero Enter the missing values Model error s The composition of layer name not specified The stoichiometric coefficients of the indicated layer in the atom location matrix of the Model window are not set or all are zero Enter the missing values Model error s The same element and line must be selected in two different chemical states When the Oxide Layer model is used the selected main constituent element and its photoelectron line must be the same for both the bulk and the layer Model error s The model system is defined but too many or necessary elements omitted The described model is defined but neglecting the elements marked as Omit in the Model window it became ill defined Remove the omit marks until the system becomes defined again 112 Model error s The model system is ill defined Specify at least N independent elements The described model is ill defined The equation system cannot be solved Each layer and the bulk must have at least one independent element For automatic fitting of the coverage one of the islands must have two in
80. ers on Plane model without using of the oxygen Angle Dependent Set on Silicon Single Crystal Si ARXPS mqd XPS data were recorded at various take off angles 0 30 60 on a silicon wafer covered with a native oxide and a hydrocarbon contaminant layers The Si2p lines were decomposed to SiO and Si components Si 2p Si 60 a a ee ee ee ee ee ee ee ee ee ee 108 104 100 96 92 Binding Energy eV Thicknesses of the oxide and contaminant layers were calculated by the Layers on Plane model with the Angle dependent experiment set feature 38 The surface of the sample showed oxygen surplus thus the composition of the oxide layer was selected as S102 SiO OH 2 Applying of SiO layer composition gives practically the same results but the differences between the measured and calculated oxygen intensity values are larger When Angle dependent experiment set is selected all experiments calculated together and the results are displayed only in the first row of the Layer Thickness window Si3N Powder SiN powder mqd XPS data were recorded on silicon nitride powder samples prepared by various manufacturers These powders consisted of nearly spherical particles The structure of the particles was assumed as follows a core of SiN is surrounded by a SiO layer and a carbonaceous CH contaminant layer Application of the Layers on Sphere model gives realistic results while the Layers on Plane model overestimates the thickness o
81. f the layers providing higher usually improbable values T i Spherical model Planar model CUPE dc dsio A dcm dio A A 10 83 1 84 16 92 2 36 B 3 95 16 51 6 73 23 50 C 4 82 8 39 8 06 12 12 D 5 06 1 56 8 46 22 E 7 32 19 16 11 88 26 14 F 6 89 3 75 11 23 5 28 G 12 74 Zo 19 59 3 19 Some hints to perform these calculations First switch to Homogeneous model to estimate quantity of the different components Higher oxygen content means higher SiO layer thickness etc Then switch back to the Layers on Sphere model estimate the layer thickness and step by step refine the fitting minimising the Qsum value Simulation of Angle Dependent Set Si02 simulation mqd The assumed sample is a silicon wafer covered by silicon dioxide and carbonaceous contamination layers measured at various tilt angles The example file is ready for the angle dependent intensity simulation Angle values are already entered into the Tilt label set in the ntensity window before the calculation The intensity of oxygen or any other element is set to 1 or any other number larger than zero to prevent deleting of empty all zero experiments by the automatic counting During the simulation do not select the Angle dependent experiment set checkbox in the Model tab of the Parameters window Invoke the Intensity Simulation window and enter identical set of thickness values for each experiment Keep in mind that these are corresponding experiments on the same
82. f the layers according to atomic weights given in the Element window and stoichiometric coefficients given in the atom location matrix of the Model window 70 Calculate Valence Electrons Calculates the number of the valence electrons for the TPP 2M formula according to the composition given in the Model window This command must be invoked from the IMFP amp Contamination window Calculate IMF Ps Calculates the IMFP values using the method selected in the Parameters window Results are put into the IMFP matrix of the Model window Parameters of the calculation are taken from the JMFP amp Contamination window Simulation Displays the ntensity Simulation window Create Depth Scale Calculates a depth scale from the Time labels and the Sputter rate value from the Labels tab of the Parameters window Depth values are permanently stored in the Other Numeric label set Warning message is displayed when the Other Numeric labels are not empty or the sputter rate or time data are not entered It works only when performed from the Composition window Data Wizard Invokes the Data Wizard window The Data Wizard helps to enter data for a simple XPS MultiQuant calculation by giving step by step instructions To leave the wizard perform this command again or press the close button Windows Menu Tile Horizontally Tile Vertically Horne vo Intensity Cascade Arranges the open windows in cascade form Tile Horizontally Arra
83. fferent chemical states of the same element e g your sample contains carbon in carbonate form and has hydrocarbon contaminant on it If the automatic contamination control Mohai is selected the State of the contaminant Cls line must be left empty To improve the reliability of the calculations you can apply more than one spectral line to quantify the same element To switch on the Multiline approach feature select the Average simple average or the Ebel weighted average method on the Model tab of the Parameters window If the element calculated by multiple lines is present in more than one chemical states you must provide data for all lines and all states for this element E g 1f you measure the Si2s and S12p lines of oxidised silicon either you can calculate the total Si concentration by the Si2s total and Si2p total lines or both lines must be decomposed into Si and Si chemical sates by the S12s 0 Si2p 0 Si2s 4 and Si2p 4 lines The binding energy values of the library used for calculating the analyser transmission and IMFP correction are approximate values usually for elemental state However you can enter the exact value to emphasise the chemical state The number of the elements is counted automatically so do not leave empty lines between them Finishing with the Element window close it by clicking the close button or by the View Elements command The values entered to the table are checked and you will get an er
84. ficients of the stoichiometric formula Oxide Molar Nj 0 DUN 0 J where o is the number of atoms i in one mol of oxide R 100 43 Oxide Molar Ratio N o p DIELL n 44 Np Oj Mass R Now 100 45 2 Nj w j where w 1s the atomic weight of element i Mass Ratio N w R i Np 46 Np Wj Oxide Mass R Nowi 100 47 2 Nj 0 W j Oxide Mass Ratio N 0 W pes ree PRE Np 48 Np Oj Wj When one of the oxide type normalisation is selected the oxygen balance is also displayed which is the ratio of the measured and calculated required by the other elements at a given oxidation state oxygen concentration If it is less than 1 the surface is deficient in oxygen if it is greater than 1 there is an oxygen surplus When the percentage forms are selected any element can be omitted from the 100 sum 48 Models for Structured Surfaces When the surface of the sample is covered by one or more thin overlayers the whole structure should be thinner than the information depth of the XPS measurement and the compositions of these layers are known the thickness of the layers can be estimated from the photoelectron intensity The program solves the inverse task the relative intensity values are calculated from the layer thickness The measured intensity data are corrected for cross section angular distribution and analyser transmission using equation 5 with the following sensi
85. g Islands l 2 3 4 5 On the View menu click Parameters Click the Model tab Select the Islands check box Select the Fit coverage automatically check box if required Setup the model as described previously In the Model window double click the Type row to mark layers as Layer or Island Notes To calculate the coverage automatically one layer in the islands must have at least two independent elements 30 Defining Repeated Layer Structures On the View menu click Parameters Click the Model tab Select one of the required layer model types l 2 3 Click Multilayers and select the required repetition number 4 Click the OK button 5 Setup the model as described previously Define one unit of the repetitive structure Defining Layers with Equal Thickness 1 Setup the model as described previously 2 Double click the Link to row in the Model window until the sequence number of the layer to be linked appears Defining Angle Dependent Experiment Set On the View menu click Parameters Click the Model tab Select one of the required planar model types Select the Angle dependent experiment set check box Click the Labels tab Click Tilt Select the required angle unit Click the OK button Setup the model as described previously oe Ae es ee ee Calculate layer thickness as described previously Notes e The data file must contain one set of corresponding experiments only e When the Angl
86. g cm The values of the k parameters for the different material classes are listed in the next table k k2 Elements 3d Ti Cu 0 0020 1 30 4d Zr Ag 0 0019 1 35 Sd Hf Au 0 0019 1 45 other and Y 0 0014 1 10 Inorganic compounds 0 0019 1 30 Organic compounds 0 0018 1 00 For the uncertainties of the IMFP values calculated by the two latter methods see literature 9 and the references therein Cumpson and Seah 12 developed the CS2 semi empirical equation 29 to calculate attenuation length in any solid over the energy range 100 2000 eV These equations take account of the correct low energy elastic scattering behaviour of large Z elements E Aa 0 316 4 59 Ere oe where a is the lattice parameter or monolayer thickness calculated by Equation 18 EF is the kinetic energy Z is the average atomic number The program expresses the calculated inelastic mean free path in A or nm unit as it is selected by the user except the first two methods where a proportional number is estimated instead of the real IMFP Transmission Function In the first approximation the analyser transmission 7 is proportional to a function of the kinetic energy This function is usually exponential 45 T E 30 where a can be selected by the user or is pre set for some frequent cases More precise approximation of the analyser transmission function can be applied by exponential polynomial or rational
87. he File menu click Print and click the Eject Page button Notes Selection of items to be printed can be saved by the Save Defaults command For the first occasion click the Option button set the preferred print options printer page orientation font and save them by the Save Defaults command Editing Elements and Experiments On the View menu click Elements Click the sequence number of the element to highlight a row On the Edit menu click Delete Rows to remove the selected element from the calculation On the Edit menu click Insert Row to add a new empty element line above the selected row Fill the line immediately On the View menu click Intensity Click the sequence number of the experiment to highlight a row On the Edit menu click Delete Rows to remove the selected experiment from the calculation On the Edit menu click Insert Row to add a new empty experiment line above the selected row Fill the line immediately Notes More than one elements or experiments can be highlighted in order to delete them simultaneously To add a new element or experiment to the end of the calculation set just fill the last empty line in the Elements or Intensity window 28 Setting up Structured Model U E pe Sy e 9 10 11 On the View menu click Parameters Click the General tab Select the Measurement unit as preferred Click the Model tab Select the required model other than Homogeneous Set
88. he Layers on Polyhedron model is used the total width of similar segments Aa Aa Aas is proportional to the geometry correction factors Minor facets with small projected area may not be displayed in the figure The window displays the recently calculated experiment To show other experiments click the sequence number of the required experiment in the Layer Thickness window The number of the selected experiment is displayed in the title bar A pop up menu activated by a right mouse click is available to copy the content of the window to the clipboard as device independent bitmap and to switch on or off the colours and the legends of the figure The content of the window can be printed by the File Print Current menu command it is printed immediately on a separate page The pending page is printed before the figure 87 Parameters Most of the parameters of the calculations are set in this window The whole content of Parameters except Title can be stored in the registry as default by using the File Save Defaults command Items not applicable in the current parameter set are dimmed but saved Enter or select data in every necessary tab then press the OK button to accept or the Cancel button to reject the changes By pressing the Apply button changes of parameter can be accepted without closing the window Press the Print button to print the current parameter set After printing parameter changes cannot be rejected even by pressing th
89. he table Labels for the experiments can also be entered into this table Labels are used either to identify experiments or to supply additional information e g the treatment time or tilt angle etc They also act as a source of X axis values for charts Select or define the required type of labels in the Labels tab of the Parameters window The content of the header row chemical symbol line assignation and chemical state may vary according to the actual elements and lines If the content of the header seems to be improper double click the table 78 IMFP amp Contamination a Time min T Cr C 5i Contam 1 o 30 26 34 37 2 10 27 26 a 34 3 20 27 26 Jl J4 4 30 27 26 a 34 5 40 27 26 a 34 B 50 a7 26 a 44 7 9 9 10 Data from the IMFP amp Contamination window are applied when separate values are used for each experiment to calculate the IMFP The layout of the window is depending on the selected calculation method Enter the inelastic mean free path data into the columns marked by element symbols for Explicit values into the above table Parameters for the Jablonski Seah Dench or Gries methods material class density g cm and mean atomic weight can be entered into the next style table E Time min Class At wegh Density Contam B 1 0 Polymer 2 10 Inorganic 2 5 3 20 Inorganic 2 5 4 730 Inorganic 25 5 40 Inorganic 42 6 50 Inorganic 42 H E J 10 Also enter contaminati
90. heir given absolute outer radius 21 and wall thickness 22 are also tested The effective thickness values of the layers and the wall for each segment are calculated by Pythagorean equations 58 60 d b h Rd 2i 1 Rea 58 b h R 2i 1 Rid 59 h 2 ay Reo 60 where R is the outer and r is the inner radius of the nanotube d is the layer thickness d b and h are the effective thickness values of the layer wall and the hole of the tube respectively s is the number of segments 9 and i is the index of the actual segment varying from 1 to s The triangles used for these calculations are illustrated in the next figure 58 The most characteristic arrangement of the randomly piled nanotubes is not the parallel but the crossing position at various angles When two tubes are in such position all segments of the two tubes are overlapping with each other The projected area of the overlapped segments are equivalent and the their ratio is invariant to the crossing angle of the tubes as illustrated in the next figure The further underlying tube rows are supposed to be parallel with the corresponding upper rows 1 with 3 2 with 4 etc The latter assumption does not really affect the accuracy of the calculations because the contribution of the lower rows is usually less than one percent The segments are situated symetrically on both sides of the tubes thus only one quadrant of the crossi
91. here the number of independent equations is equal or greater than the number of variables at least one independent element per layer is necessary n 1 elements for n layers bulk For sland type models one more elements is necessary in one of the islands to calculate coverage Intensity data of elements being present in more than one layers are summed unless its spectra can be decomposed into different chemical states use the State column settings in the Elements window Sometimes the system cannot be well defined e g single element islands on a single element substrate In these cases consider applications of different calculation methods like Tougaard s QUASES program or record spectra at more than one take off angles 49 The Autofit procedure minimizes the sum of the squares of m non linear functions number of layers in n variables number of elements m lt n by a modification of the Levenberg Marquardt algorithm 16 The Jacobian matrix is calculated by a forward difference approximation The procedure is called repeatedly with decreasing tolerance limits until the best fit is achieved Unless the model system is converging very slowly this method supplies the optimal fit in one step If the convergence is slow Autofit may stop due to reaching the allowed maximum number of iterations without obtaining a solution to the accuracy specified Try to invoke Autofit some more times The slow convergence may indicate that the model
92. i i a ala 2R cove RF 57 j 1 j 1 where R is the total radius bulk plus layers and the term R 2d stands for the radius of the core under the current layer If the radius is even smaller 1 e R 3A this model cannot be applied because there is no bulk like material After intensity values being calculated for every segment they are weighted by the corresponding geometry correction factors G1 G2 etc see the previous figure describing the projected area of the spherical zones The flattened surface of powder samples is similar to the closest packed plane of the hexagonal lattice The specific feature of this section 1s that some parts of the second and third rows of spheres below the top one are also visible partially as illustrated in the following figure The geometry correction factors G also include these contributions If the sample consists of relatively large spheres e g small balls arranged in one row the latter correction can be turned off In this case the material of the sample holder is visible among the spheres thus it should not contain any element of the sample including the possible contaminations carbon oxygen etc Using a piece of gold foil is usually advisable When this model is applied the angle of emission take off angle cannot be varied 1 e the sample must be observed from the direction of the surface normal 0 is zero and cos 1 53 Layers on Cylinder Model 0 d
93. ickness values Library access error Fatal software or hardware error occurred during library lookup Library disabled Library lookup is not allowed Enable searching of the library in the General tab of the Parameters window Library not found File XMQ LIB must be in the application s folder The library file cannot be found in the application s folder Move the library to the correct location or reinstall it from the distribution media Line symbol not found The selected photoelectron line of the specified element is not included in the selected cross section data set Select other line from the list of the available lines select other cross section set or try the splitting and scaling features Maximum number of iterations reached The allowable number of iterations has been met without obtaining a solution to the accuracy specified in the program Very slow convergence may be indicated Try to invoke Autofit again Model error s Bulk or layer element not marked When the Oxide Layer model is used the chemical states of the main constituent element must be denoted by Me for the bulk and by Ox for the layer Model error s Geometry correction factors of the Layers on Polyhedron model not specified The Layers on Polyhedron model is selected but the geometry correction factors are not specified Invoke the Polyhedron Editor window from the Model tab of the Parameters window and edit geometry data Model erro
94. intensity calculations using the same equations as those applied for the Layers type models are performed in two steps The island and non island parts are computed separately then weighted by and 1 9 respectively The corresponding intensity values of the two calculations are summed The same method is used for the curved surfaces slands on Sphere Islands on Cylinder Islands on Polyhedron thus the following restrictions are assumed the islands are relatively thin and small comparing to the radius of the surface and uniformly distributed on the spheres or cylinders 1 e the same amount of island and non island areas are present on any part of the surface The sidewalls of the islands getting visible on the high angle segments of the curved surfaces or at tilting of the planar samples are left out of consideration When the islands are thin enough as compared to their area this effect is usually negligible In case of the s ands on Plane model the angle of emission Tilt is applied 60 Since a new independent variable is introduced to the calculations the system may be ill defined the number of independent equations is less than the number of variables e g both the island and the substrate contain single element only In this case either the island thickness or the coverage should be supplied from other measurements A few examples for some of the possible arrangements are given in the following t
95. ions like XPS MultiQuant are installed into the Program Files x86 folder XPS MultiQuant data files mqd can be stored on any drive in any folder Although the language of XPS MultiQuant is always English it applies the locale settings of your system in the Control Panel Regional Settings as different decimal and thousand separators date formats etc except in the analyser transmission files 11 Using of the Program This chapter describes the first steps of using XPS MultiQuant The basic knowledge of X ray photoelectron spectroscopy and Microsoft Windows is assumed Starting XPS MultiQuant The program can be started by several ways as usual in Windows Press the Start button and select XPS MultiQuant from the Programs folder Put a shortcut to the desktop and double click it Double click the icon of any XPS MultiQuant data file with mqd extension Previously processed XPS MultiQuant data files are also available in the list of the Start button Documents When the program is running the main window may look like this File Edit wiew Tools Window Help Merge chemical states Number Atomic Es 0 Ti Ag Si l 24 3 2il 27 8 29 1 29 3 30 1 30 3 30 0 25 0 27 6 Op 2 Oo CTT Re a a co oo Mer Pes l t Z Cross Atomic aU Time min C Program Files MOSS amples Contact mad 12 When the program is started by clicking a data file or f
96. is selected enter also the source energy Select the Enable library lookup check box 10 Click the OK button 11 On the File menu click Save Defaults Notes When the program is started at the first time none of these parameters is set 1 e numeric values are zeros and methods are None etc The default parameters are applied when a new calculation is started Any of these parameters can be changed later at any stage of the calculation 26 Setting up Simple Quantification On the File menu click New In the Elements window type the chemical symbols and line notations into separate columns of the elements involved in quantification e g C 1s O Is Cu 2p etc On the Tools menu click Library Lookup On the View menu click Intensity Enter the integrated intensity peak area data for each experiment Type the experiment labels name etch time etc as well On the View menu click Results On the View menu click Parameters Click the General tab or double click the Title leftmost panel of the status bar Enter a descriptive title for the calculation and click the OK button On the File menu click Save As Enter a filename for the calculation and click the Save button Setting up Multiline Calculation l Setup simple quantification as described previously Enter more than one photoelectron lines 1f available for each element or as many as possible e g S2s and S2p Cu2p and Cu3p and Cu3s etc
97. itely thick sample is described by equation 1 dl oNkexp x Acos dx 1 where is the intensity is the X ray flux o is the photoionisation cross section N is the number of atoms per unit area k is an instrument factor is the inelastic mean free path IMFP O is the angle between the exiting electrons and the surface normal and x is the distance perpendicularly below the sample surface 1 2 Integrating the above by x from 0 to infinity the total intensity can be determined I OMoNkAcos 2 If the sample is covered with an overlayer of d thickness e g surface contamination equation 1 must be integrated from 0 to d and from d to infinity to get the intensity from the surface layer 3 and the bulk 4 I DoNkAcos6 H exp d dcos6 3 P oNkAcos6 exp d Acos 4 41 In the practice instead of absolute intensity intensity ratios are used thus the constant 1 e energy independent parts of the equations kcos can be neglected The measured intensity should also be corrected by the transmission function of the analyser and also detector sensitivity by the cross section which accounts for electrons exited into every directions 1 e 4r sr solid angle and for the angle of detection Thus the relative concentration of atom 7 in an infinitely thick homogeneous sample covered by surface contamination can be calculated from the total intensity by the following equations N ily 5 I F 0
98. itional information connecting to the calculations to store together with the XPS MultiQuant data This window is not restricted to the main window it can be kept open and remarks can be written continuously during analysis of data Editing functions are available via standard or pop up menus see chapter File Menu Notes window A similar window is applied for editing the current transmission file 101 Intensity Simulation Islands on Plane Experiment at Empty Thickness nm 0K Calculate The input data layer thickness and coverage of the intensity simulation calculations can be entered into the small table of the Intensity Simulation window If the intensity data set is not empty 1 e all zero a warning message is shown before displaying the window Model Displays the current quantification model type Experiment Select the number of experiment where the results of the simulation intensity values are stored The status of the current experiment can be Filled if at least one intensity value of the current experiment is not zero either manually entered experimental or simulated can be Empty if all values are zero or temporarily Calculated to indicate that calculation with the current data just has been done Name Enter the name of the simulated experiment to store in the Name label set If it were left blank the word Simulated is inserted The automatic labels can be edited and other label
99. k where N is the average unnormalised concentration of element i Ni is the unnormalised concentration of element i calculated from line When applying the method of Ebel et al 6 data points are weighted by the square root of the intensity representing the strong signals by heavier weight as compared to weak ones To find the optimal unnormalised concentration the weighted error quantity shown by equation 40 is minimised for each element 2 IK min gt In k InN Jis 40 k i where Z is the measured integral intensity F is the sensitivity factor N is the unnormalised concentration The 7 index stands for the elements and the k for the lines of that particular element Normalisation of the Results The applied quantification gives relative concentrations thus the results should be normalised The results can be displayed in various forms as required by the further applications The meanings of R variables in the following equations are the same i e normalised concentration although their numeric values are different Atomic Rj 41 N 100 2N J where N is the relative concentration of element i from equation 5 and R is the normalised relative concentration The j index is varied from 1 to the number of elements 47 Atomic Ratio N Ri Np 42 Np where N is the relative concentration and n is the number of atoms of the selected basis element This mode supplies the coef
100. lect other basis element Vary the layer thickness and coverage data until Qsum 1s less than 50 then invoke Autofit again Results error s Carbon not found No contamination correction Mohai s contamination correction method is selected but no Cls line with empty State field was found Select different method add Cls line or clear the State field of the adventitious carbon 114 Results error s Invalid transmission data No transmission used Some of the coefficients in the transmission file are too large to calculate the transmission function or some of the calculated factors are negative or zero Edit the transmission file to fix the error Results error s Oxygen not found in experiment N One of the oxide normalisation types is selected but oxygen was not found in the N experiment the oxygen intensity 1s zero or empty there is no oxygen among the elements Some of the results are out of the expected range Refine initial data or modify the model Although the fittings of the parameters was successful mathematically some of them has no physical meaning e g negative layer thickness layer thickness greater than five times of the largest IMFP value coverage less than zero or greater than one Some parameters of the IMFP calculation are out of the expected range or missing Some parameters of the Seah Dench Tanuma Powell Penn or Gries inelastic mean free path calculation are out of the expected range 1 e the material
101. liminated see Equation 7 Cross sections were calculated using E IMFP and F transmission dependency The data of Wagner et al 1 29 are experimentally based relative sensitivity factors Measurements were performed with Mg Ka and Al Ka radiation fixed analyser transmission mode FAT CAE at 84 analyser excitation angle and also with CMA analyser Values are average for Mg and Al radiation the strongest lines are insensitive to the excitation while secondary lines should be corrected by 0 9 and 1 1 for Mg Ka and Al Ka respectively The data of Nefedov et al 30 31 are experimentally based relative sensitivity factors relative to Nals 1 Data were recorded with Al Ka radiation fixed analyser transmission mode FAT CAE Average Scale Factors The three average scale factors Evans Scofield Wagner Scofield and Nefedov Scofield for scaling the cross sections or sensitivity factors are calculated as the average of the ratio of all available corresponding photoelectron line pairs 158 200 and 57 items respectively see Equation 10 Asymmetry Parameters The theoretically calculated asymmetry parameters of Rei man et al are given in reference 4 in tabulated form for the different transitions in five atomic number steps Polynomials with order of 6 were fitted to every asymmetry parameter set and the coefficients together with the transition names and the ranges of validity atomic numbers are stored in the libr
102. ls General Model Layers on Sphere Islands Multiline approach None F Single row of Spheres Sphere or Cylinder radius Modified tube layer Tube inner radius Multilayers Fit coverage automatically Angle dependent experiment set Edt Pririt Cancel Apply OF Model Select the required model for the sample Homogeneous infinitely thick homogeneous sample optionally with surface contamination Oxide Layer planar samples with one overlayer containing different chemical states of the same element Layers on Plane planar sample with known composition covered by 1 to 5 overlayers Layers on Sphere spheres in closest packed or single row arrangement with known composition e g coated powder pellets covered by 1 to 5 overlayers Layers on Cylinder cylinders with known composition e g coated fibres covered by 1 to 5 overlayers Layers on rough surface modelled as planar facets of polyhedrons covered Polyhedron by 1 to 5 overlayers Layers on Nanotube randomly piled nanotubes covered by to 5 overlayers Islands Select this check box if non continuous overlayers islands are present on the sample Single row of Spheres Select this check box if the relatively large spheres of the sample are layed in one row 97 Modified tube layer Select this check box if the layer on the nanotube was prepared by modification of the tube material 1 e the Sphere or cylinder radius is the sum of the l
103. lso the data file must contain the related angle dependent experiments only In the simplest case when a metal is covered with its native oxide and the two chemical states of the metal can be resolved the Oxide Layer model can be applied The thickness of the overlayer is calculated directly based on the intensity of the metal lines originated from the bulk and from the oxide layer The layer must be defined in the Model window as described previously composition molecular weight density IMFP The two chemical states of the main element must be denoted as Me metal and Ox oxide in the Elements window For inserting the special state information quickly rotating text in the Me Ox empty order you can double click the appropriate cells of the State column Intensity Simulation For several reasons theoretical studies test purposes etc it is useful if the usual quantitative calculations can be done backwards 1 e from the layout and the predicted composition of the sample the integrated photoelectron intensity values can be obtained Actually the program always solves this inverse task 1 e intensity from layer thickness and eventual thickness data can be reached only by parameter fitting Just adding a new data flow to the program was necessary To prepare simulated data select the required elements and set up a structured model as described in the previous chapter Invoke the Intensity Simulation window b
104. ly Scaling Select the method of scaling of the theoretical cross sections into the experimental data sets in case of missing experimental values None no scaling 1s applied Closest line scaled by the ratio of the closest line Average factor scaled by the average of the ratio of all available line pairs IMFP Tab Contamination Model Labels General Cross section IHEP ye Method Explicit i att Exponent 0 7 Maternal class Inorganic ka Density 1 5 g cm Use separate values Mean atomic z0 Calculate mean atomic weight weight Pririt Cancel Apply UF 90 Method Select the applied inelastic mean free path correction method None no IMFP correction Explicit exact IMFP values given by the user are used Exponential exponential approach Jablonski Jablonski s exponential approach with pre set exponents Seah Dench formula of Seah and Dench Tanuma Powell Penn TPP 2M formula of Tanuma Powell and Penn Gries G 1 formula of Gries Cumpson Seah CS2 formula of Cumpson and Seah attenuation length Exponent Enter the exponent of the Exponential approach Material Select the material class for the Jablonski Seah Dench and Gries methods when the same values are used for all experiments It can be Element Inorganic or Polymer Density Set the density of the material in g cm for the Seah Dench and Gries methods when the same values are used for all experiments Mean atomic weight Set the me
105. ments are handled together Calculation can be initiated by double clicking any experiment of the set but the intensity results calculated for the whole set is compared to the selected experiment only Layer Calculation Elements Measured Ditt Calculated relative intensity i roo om 1o 1000 000 T oao ooo o440 osz coool Element 0 Uae 14 54 0 638 0 514 0 000 intensity T 0 372 oo o972 o5 Good Layers nm sum 0 0118 0 2124 2665 CH di 1 39 1 00 0 00 Side Lae 257 200 0 00 TAE E ESSE Coverage oeo new ooff Coverage Experiment Ez Autotit Cancel OK 84 The upper part of the table shows the results of the intensity calculations The Measured column shows the measured intensity ratio as described in chapter Models for Structured Surfaces The basis element can be changed by double clicking the element symbol When an element is omitted from the automatic calculation instead its sequence number an X is shown in the first column The omit sate can also be changed in the Layer Calculation window by double clicking the sequence number of the element The lower part of the table shows the actual and previously entered layer thicness and coverage values When two layers are linked they indicated by the same layer number When a layer is fixed or the coverage not fitted automatically a letter F is displayer instead of the layer number After typing the layer thickness values into the entry cells of the table
106. n are summarised in the Layer Thickness window The geometric scheme of the applied model can be displayed in the Model Layout window There are some other characteristics to help defining more complex models If you have some a priori knowledge on the relation of the different layers you may declare the thickness of different layers to be equal double click the cells in the Link to row in the Model window until the number of the target layer appears Furthermore if you know that the layers are repeated on the sample it is enough to define the unit and to select the number of the repetitions in the Multilayers box in the Model tab of the Parameters window The typical application of these features is the study of Langmuir Blodgett type films If you record the spectra of a planar sample at several take off angles angle dependent XPS ARXPS the thickness of the layers can be calculated using all of the experiments together with the Layers on Plain and Islands on Plain models N e 20 This technique increases the number of independent variables 1 e the elements and you may calculate systems which is ill defined when measured at one take off angle only typical example is single element islands on a single element substrate To use this feature select the Angle dependent experiment set check box in the Model tab and select the Tilt labels in the Label tab of the Parameters window The calculation set and a
107. ng tubes 9x9 segments only 3x3 shown needs to be calculated When the layer on the nanotubes is prepared by modification of the tube material e g by plasma or chemical treatment the overall original diameter of the tube is unchanged but the thickness of the undisturbed tube wall is decreasing with the increasing thickness of the modified part their sum is equal with the original thickness of the tube wall 59 During this type of calculations the total thickness is kept constant and the actual wall thickness 1s also iterated This latter variant of the model can be applied for one layer only The number of rows of nanotubes to be involved in the calculation 7 is determined by the following empirical equation 61 Now 3 4 4 jima 0 75 61 where d is the thickness of the nanotube wall and Ay is the largest IMFP in the material of the wall The formula intentionally overestimates the number of necessary rows now Which falls between 1 and 6 Island Type Models bulk Mk Frequently one or more of the surface layers covering the surface are not continuous forms islands on the bulk material An additional parameter the coverage varying from 0 to 1 describes the relative area of the islands Any of the overlayers can be present as island marked by I in the figure but the coverage must be the same for all of them In addition to the islands continuous layers may also be present L The
108. nges the open windows horizontally tiled 71 Tile Vertically Arranges the open windows vertically tiled Home Moves the active window to the home position upper left corner of the main window Help Menu F j ag ea a J i oe 1 ee a alin File w Tools Window Help Help Topics Context Help What s This About APS MultiQuant Help Topics Displays the table of content of XPS MultiQuant Help Context Help Displays context sensitive help What s This Changes the mouse pointer to What s This pointer question mark Click an item to display its context sensitive help in a pop up window About XPS MultiQuant Displays the program s About box It shows the version numbers of the program library and data files 72 File Menu Notes window 5 E Print Sa pme Exit Print Prints the notes text and saves the last editing Exit Closes the Notes window after prompting to save any unsaved editing To permanently save notes use the File Save command to save the current XPS MultiQuant data file Edit Menu Notes window File Edit Format Help Undo Cut Copy Ctrl C Paste Delete Select All Ctrl A Undo Revokes the last editing action There 1s only one level of undo Cut Copy Paste Delete These commands provide standard editing functions to cut copy paste or delete text They can also be accessed via pop up menu right click Select All
109. nly when the Layers on Polyhedron model is selected 98 Labels Tab Cross section IMFF Angular i Transmission Contamination Model Labels General F Sequence number W Name Time no Convert time to depth Tilt Sputter rate 2 00 nmin Treatment Other text IT extLabel Other numeric NumLabel Pririt Cancel Apply OK Iw a Temperature m Select the check boxes of labels to be displayed Select the measure from the dropdown lists for the numeric type labels Enter the name of the user definable label sets into the textboxes Preselect one of the labels as X axis value of the charts sequence number can be selected by this way only Unselected label sets cannot be chosen as X axis All label values entered in the ntensity window are stored even after deselected in this tab When the Layers on Plane or Islands on Plane model is applied tilt angle 0 values are taken from the Tilt label set If both the Time and Convert time to depth check boxes are selected time data will be multiplied by the Sputter rate value and instead of time depth is displayed temporarily in the Composition and Chart windows Numeric data are not converted automatically when a measure is changed 99 Polyhedron Editor 40 Tiit angle of facets Tit ange 30 9 Area 16 7 H Clear Normalize Cancel OK The parameters of the sample geometry model describing the surface by small facets at differen
110. nsmission or contamination The number of atoms per unit volume Nme and Nox is calculated by Equation 50 as in the case of other structured models Unlike the other models no parameter fitting is required thus results are calculated and displayed immediately 5 on SS 981 32 Ket IB a8 r a er CEE f Bie pn Fart po GA R giujsyex aa afa ca e a Re 253 Q ba 2 mus 62 Library Data The library of XPS MultiQuant includes all necessary basic data for the calculations data for elements photoelectron lines angular correction etc Any data extracted from the library can be overwritten manually Chemical Elements The atomic number element symbol name atomic weight 1981 Table of Standard Atomic Weights density and valence data of the elements were extracted from the literature 25 The valence and number of oxygen atoms refer to the most common usually the most stable oxide Photoelectron Lines The kinetic energy of the photoelectron lines were taken from Reference 26 and converted to binding energy Some data were taken from Reference 27 The energy of the doublet lines is the mean of the two components weighted by their nominal intensity ratio 1 2 2 3 and 3 4 for the p d and f lines respectively as shown by Equation 64 E ee eth ie 64 mean la l where is the binding energy is the nominal intensity indexes a and b refer to the higher pi d32 fs2 and lower p3 2 ds 2
111. om the Labels tab of the Parameters window It can be altered easily by double clicking the label column headers Sequence number as X axis can be selected only in the Parameters window Numeric labels Time Tilt Temperature etc are treated as numbers while text labels are simply enumerated The Y value axis is chosen according to the result type in the Composition window Elements omitted from percentage calculation are also omitted from the chart even if the result type is changed to ratio If you have unnecessary data points 1 e experiments in your series e g a 60 tilt experiment in an ion etch series you may omit them from the chart by double clicking the sequence number of the experiment The number is changed to X showing that this experiment is switched off temporarily Feel free playing with different settings and find the best form of presentation which suits your requirements While you analyse your results open the Notes window View Notes command record your comments and store together with the respective data 16 Saving and Printing After entering data you may want to save them for documentation for further analysis or for extending later with new data To save your work select the File Save As command A standard Windows dialog box is shown to set or select the folder and file name The default extension is mqd The file is binary thus do not tamper it with other programs When you save the data for the first
112. on correction factors for Explicit type correction Data from this table are used only when the corresponding calculation methods are selected in the Parameters window Although these data are not always used all data are always preserved and stored in data files Labels cannot be edited in this window The content of the header row chemical symbol line assignation and chemical state may vary according to the actual elements and lines If the header seems to be improper double click the table 79 Composition Merge chemical states Number Atomic Time min T Ti Ag C Si lo 7AF 24 3 0 0 ail 2 2 70 5 27 8 0 0 1 7 3 l4 70 9 291 0 0 0 0 4 6 E84 293 0 0 24 5 g 693 9 30 1 0 0 0 0 B 10 63 7 30 3 0 0 0 0 7 12 63 8 30 0 0 1 0 0 a 14 67 3 29 0 0 7 29 g 16 64 9 27 6 1 6 5 9 10 18 62g 26 0 28 i When all necessary input data are entered invoke the Composition window by the View Results command to see the harvest of the quantitative calculations Results can be displayed in various forms From the dropdown list Atomic Atomic ratio Oxide molar Oxide molar ratio Mass Mass ratio Oxide mass or Oxide mass ratio can be selected as adequate for the application of data For the percentage type results any element can be omitted from or introduced to the 100 by double clicking the element symbol while for the ratio type of data the basis element can be selected also by double clicking the elemen
113. onstant Analyser Energy 64 93 Constant Retarding Ratio 64 93 Contamination 6 13 14 15 21 22 23 26 29 33 34 35 36 37 38 39 41 42 46 47 49 61 62 68 69 74 78 79 83 87 96 97 110 114 Convert units 89 Copying 15 17 68 75 118 Correction Angular 23 26 42 49 63 64 92 100 114 Contamination 6 13 14 21 23 26 34 35 36 37 39 41 42 46 62 78 79 87 96 97 110 114 Elastic scattering 43 121 122 IMFP 6 13 14 15 21 22 25 26 29 34 41 42 44 45 46 47 49 51 60 62 63 64 68 69 70 71 74 79 82 83 88 89 90 91 96 98 110 112 113 114 115 117 118 Transmission function 6 10 11 14 21 26 35 42 45 46 49 58 62 63 64 93 94 95 101 106 108 110 111 113 114 116 117 118 120 Cross section 6 13 21 23 26 34 35 41 42 43 49 57 62 63 64 89 90 111 119 120 CRR 64 93 CS2 formula 45 91 Cumpson P J 22 29 45 91 118 122 Cylindrical surface 19 54 55 57 87 D Data file 9 12 13 15 16 17 21 31 67 72 73 79 88 103 106 107 108 110 113 116 117 118 119 Data Wizard 13 26 71 105 117 118 Delete Element 14 28 68 Experiment 14 28 68 DELETE key 14 28 68 73 77 107 109 Dench W A 22 25 29 44 79 91 110 115 121 Density 21 24 25 29 44 45 49 63 79 82 83 91 109 110 112 115 Depth scale 71 89 Detector sensitivity 42 46 Diff 20 49 Doublet 13 15 42 43 63
114. os 1 exp c1 cos d d i Niep x17 cos dx i 54 N S cos exp a COS B te a i COS Jj P N exp x 1 cos dx d d 55 N a8 cos Bexp d COS B exp 01 10 COS B where 4 means the inelastic mean free path of the electron emitted from element i in the matrix S etc Other symbols are defined at equations 1 4 51 Layers on Sphere Model 0 di d d The calculation of photoelectron intensity excited from a spherical surface covered by overlayers is similar to the calculation of flat samples However the effective thickness of the layers the virtual thickness seen from the direction of electron analyser is varying from point to point along the sphere Thus the intensity originating from the various zones of the sample should be weighted by a geometry correction factor taking into account the projected areas corresponding to different thickness The integral describing the intensity of emission from a hemisphere cannot be solved analytically therefore the latter is divided into 9 segments of 10 17 18 Every segment is represented its middle angle 5 15 25 etc If the radius of the sphere is large enough R gt 10004 it can be neglected from the equation 56 describing the effective d get 4 56 COS O If the radius of the sphere is smaller but still R gt gt 3A it must be supplied by the user and d f is calculated by equation 57 52 Cha Icos aR
115. owever the user is responsible for the reliability of mixing the different methods and data It is important to consider weather a sensitivity factor or your input data already contain correction for a phenomenon do not apply any correction twice Switch off all unnecessary features e g if your instrument has magic angle arrangement 54 73 excitation analyser angle where the term gt cos gt is zero do not apply angular correction Cross Section Correction Evans original cross section data 3 are measured with 90 excitation analyser angle and this factor was not separated from the cross section values Before angular correction data are converted to the 4r sr solid angle but only when the Data set item in the Cross section tab of the Parameter window is set to Evans Wagner s sensitivity factors for the secondary lines are multiplied by 0 9 for Mg Ka and by 1 1 for Al Ko excitation as suggested in 1 when the above item is set to Wagner Thus this item controls not only the library search but the pre treatment of library data as well If you use manually entered sensitivity factors make sure to set this item to None Contamination As general contamination correction method of Mohai 15 is suggested see the following examples in the table especially when the sample itself does not contains any carbon This method is applicable for carbon containing materials as well when the signal from the constituent c
116. r when clicking it Data of the X axis can be changed easily by double clicking the label column header except the Sequence number it can be preselected only in the Labels tab Data points 1 e experiments can be omitted from the chart by double clicking the sequence number of the experiment The number is changed to X Elements omitted from percentage calculation are also omitted from the chart even if the result type is set to ratio If only one experiment is entered instead of the line chart a pie chart is displayed No chart is shown when only one element is specified A pop up menu activated by a right mouse click 1s available to copy the content of the window to the clipboard in Windows Metafile format The chart can be printed by the File Print Current menu command The chart is not spooled it is printed immediately on a separate page The pending page is printed before the chart The Chart window is also applied to compare the measured and calculated relative intensity values at the layer thickness calculations see chapter Layer Calculation 81 Layer 2 Layer 3 Laver 4 Layer 5 Mame CH 1 Pb Ac LH 2 Type Layer Island Layer Link to Layer 1 Hol weight 45256 319 24 432 36 Density 0 780 3 250 0 7820 Ho H r200 4 00 r200 0 4 Ou a 7 00 Atom location C 4 00 matrix Si 18 75 Pb 26 12 C 23 40 Si 26 81 IMFP matrix 0 7 2 3 4 A 4 When one of the structured model types is selected in the Model t
117. r Edit Delete Rows commands in the Elements window to insert or remove experiments use the same commands in the ntensity window The deleted rows cannot be recovered After inserting an empty row fill it immediately otherwise the automatic counting may cut the table starting from the empty line If you want to add elements or experiments to the end of the tables simply fill out the last empty line 14 Content of the cells can be easily copied and pasted within XPS MultiQuant or between external programs by the pop up menu commands invoked by right mouse click Calculator in the Input Windows Instead of numbers simple arithmetic expressions may also be entered into the cells of the input windows Elements Intensity IMFP amp Contamination Model These may be used conveniently e g for summing up the intensity of the components of a doublet line The expression consists of two numbers connected with an arithmetic operator Valid operators are addition subtraction multiplication and division Numbers may have sign decimal separator dot or comma according to the locale settings of the operating system exponent sign e or E and one or two digit exponent with optional sign The expression is parsed and calculated immediately when the RETURN or an ARROW key is pressed and replaced with the result If the expression is invalid either syntactically or semantically e g division by zero the result is not shown
118. r Thickness on Nanotube Surfaces from XPS Intensity Data M Mohai I Bert ti to be published 124 Index A Adventitious carbon 6 114 Al Ka excitation 23 42 64 Analyser excitation angle 13 23 42 64 114 Angle dependent experiment set 9 20 21 24 37 38 39 56 84 85 118 Angle of emission 21 24 39 53 55 56 60 62 78 99 100 108 ARXPS 9 20 21 24 37 38 39 56 84 85 118 ASCII 17 68 94 107 Asymmetry parameter 6 35 42 43 64 Atom location matrix 70 82 109 112 119 Atomic 16 47 80 Atomic ratio 16 80 Attenuation length 22 45 91 118 Autofit 20 24 30 49 50 82 85 108 109 110 111 114 115 118 B BACKSPACE key 14 77 107 Bandgap energy 45 83 115 Bar graph 86 Basis element 16 17 20 24 27 30 80 85 114 Binding Energy 14 62 63 115 Bulk material 19 21 24 29 30 32 41 49 51 53 57 60 61 62 82 87 111 112 C CAE 64 93 Calculator 15 118 125 Chart window 16 20 69 75 81 86 99 118 Chemical states 14 16 21 27 35 37 49 61 63 77 78 79 80 97 98 109 111 112 CH contamination 37 39 Clipboard 17 68 74 75 76 81 87 107 Combined UNIFIT function 9 93 94 95 117 122 Command 13 14 15 16 17 19 21 26 28 33 70 71 73 75 77 80 81 83 84 87 88 89 103 105 109 112 113 115 116 117 Composition window 16 27 28 71 80 Concentration 14 16 27 34 35 42 46 47 48 109 120 C
119. r Window Reading of XPS Reduced Data Exchange File version 1 1 was implemented The Oxide Layer model type was added New AL calculation method was added Cumpson Seah for the structured models The input window calculator was added IMFP and thickness measure conversion was added Enhanced selection of Autofit initial parameters fewer overflow error Reading of XPS Reduced Data Exchange File version 1 0 was implemented Extended library version 4 0 with more line entries erroneous library items were corrected New data file version 1 43 Minor bugs were corrected New application examples New chapters in the Users Manual Calculator in the Input Windows Oxide Layer Model Contact Experiments recorded at various angles of emission can be calculated together Angle dependent experiments set ARXPS New IMFP calculation methods were added Tanuma Powell Penn Gries for the structured models New data file version 1 42 New library version 3 0 Minor bugs were corrected New chapters in the Users Manual Inelastic Mean Free Path Step by Step The Model Layout window was added The content of the Chart window can be copied and printed directly New normalisation types Oxide mass Oxide mass ratio Minor bugs were corrected Parameters error caused by data files prior to version 1 20 were corrected Layer forward link data handling bug was corrected The least squares fitting of the model parameters Autofi
120. r s Inner radius of the nanotube is too large The inner radius of the nanotube is equal or greater than the outer radius Model error s Layer N not defined Definition name of the N internal layer is missing There is an empty column between the defined layers 111 Model error s Link error at Layer N chains or cross links The target of a link cannot be a linked or fixed layer neither directly nor indirectly Chains e g Layer Layer 2 Layer 3 or cross links e g Layer 1 lt gt Layer 2 are not allowed Check the Link to row in the Model window Model error s Missing IMFP data One or more IMFP data is missing from the Model window Apply the Tools Model Mark Unused IMFPs command and fill all unmarked cells Model error s No bulk defined When structured models are used at least one layer and the bulk must be specified The Name field must be filled in the Model window Model error s Only one layer allowed for the Oxide Layer model When the simple Oxide Layer model is used only one overlayer on the bulk can be defined If more layers are necessary use the Layers on Plane model Model error s Radius of the carbon nanotube seems to be too small The absolute radius of the carbon nanotube is smaller than the minimal value specified in the literature Model error s Radius of the nanotube must be specified The external radius of the nanotubes cannot be omitted as in case of spheres or cylind
121. rent starting values Always check whether a layer is really discontinuous When the number of independent parameters is increased by the coverage the numeric value of the fit may seem to be better but it does not necessary mean that it really 1s Density of Layers A layer deposited or developed on the surface of a substrate e g a native oxide layer grown on a metal surface may be far less dense than its bulk density Using the latter value may decrease the calculated layer thickness significantly as compared to the thickness measured by scanning probe microscopy or by optical methods It is also called angle resolved XPS ARXPS but it is better to reserve this name for those experiments where the angle between the analyser and the excitation source is varied 24 IMFP for Homogeneous Model For the homogeneous model instead of the absolute IMFP values only their ratios are relevant When the IMFP values are calculated by predictive formulae like formula of Seah and Dench 8 or Gries 11 even at altering the parameters mean atomic weight density in a wide range the ratio of the different IMFP values remain almost unchanged and accordingly no differences can be observed in the composition results Thus for homogeneous model calculations precise knowledge of these parameters are not essential However for the structured models knowledge of the actual IMFP values is fundamental 25 Step by Step This chapter give
122. rom the Start button Documents the file is loaded and the results are calculated and displayed automatically The main window can be resized and repositioned as usual in Windows At the top of the window you can find the customary menu bar At the bottom the status bar shows the title of the calculation the name of the current data file if any the pending page and the status of the NUMLOCK key If you are unfamiliar with XPS MultiQuant invoke the Data Wizard in the Tools menu It gives you step by step help how to fill the different tables of the program Setting Parameters It is a good practice before entering the input data for your quantitative calculations to set all of the parameters required especially when you start XPS MultiQuant at the first time Most of the parameters have to be set only once unless you are lucky to have more than one spectrometer or one with several operating modes Perform the View Parameters command and scan through the tabs and set or select the following items e Model type usually Homogeneous e Excitation source e Cross section or sensitivity factor set Usually let the Enable library lookup and Splitting features enabled e Method of inelastic mean free path correction Try a simple exponential approach first e Angular correction and the excitation analyser angle of the instrument e Method of contamination correction For general use selection of Mohai is suggested e Transmission func
123. ror message if some of them are unrealistic When all element data are typed in invoke the ntensity window by the View Intensity command Get the integral peak intensity data from your XPS data processing software after the usual pre processing correction for acquisition time number of sweeps background removal etc and enter them into the table of Intensity window In case of your data are also corrected for analyser transmission set this feature to None in the Parameter window The program distinguishes the empty and zero cells so you can use zero value to emphasise the absence of an element while an empty cell may simply mean not measured If your data system 1s able to provide intensity data in tabulated form as specified in chapter Program References Edit Menu you can enter all of the data in one step using the Edit Paste Table command Type the labels for your experiments Although contents of the labels are not checked enter only numbers into numeric label cells otherwise they are treated as zero The number of the experiments is calculated automatically do not leave empty lines If you apply more sophisticated IMFP or contamination correction you have to fill the corresponding fields in the JMFP amp Contamination window as well The content of any input window can be changed later at any time To edit the content of cells use the BACKSPACE and DELETE keys To insert or remove an element use the Edit Insert Row o
124. rst line is applied in the kinetic energy range of 100 499 9 eV the coefficient set of the second line is applied in the kinetic energy range of 500 1499 9 eV etc In the third example coefficients of the rational function are given in two lines without indication of energy ranges In the fourth example coefficients of the combined function is given in single line without energy 95 Contamination Tab IMFF Angular Transmission Contamination Model Labels General Method Mohai Contamination factor l2 F Use separate values Frint Cancel Apply OK Method Select the applied contamination correction method None no contamination correction Evans static method of Evans Mohai dynamic method of Mohai Intensity data for Cls line must be present Explicit factors for contamination correction are entered into the IMFP amp Contamination window Contamination factor Set the contamination factor for the Explicit method when the same values are used for all experiments Use separate values Select this check box if separate contamination factor values are specified for each experiment in the JMFP amp Contamination window for the Explicit method If the automatic contamination correction method Mohai is selected a Cls line with empty State column 1 e the contaminant must be present in the Element window 96 Model Tab Cross section Angular Transmission Contamination Labe
125. s can be added later in the ntensity window OK Closes the ntensity Simulation window Calculate Calculates intensity values with the current thickness and coverage data and stores them in the selected experiment 102 Print Print hat Input data Results W Parameters W Atomie Elements W Atomic ratio IMFP Oxide ratio Model W Mass Motes Mass ratio Oside mass 2 File name Oside mass ratio Options Lancel Eject Page Iw M Intensity Oxide 2 Print What Select the items to be printed When File name is selected the name of the current data file is printed after the header These settings are stored in the registry when the File Save Defaults command performed Options Invokes the Print Options window Cancel Closes the window without printing Eject Page Prints of the pending the last unfinished page Print Prints the select the items Only full pages are printed using the spooling feature of the operating system Unfinished pages are printed only when the Eject Page button is pressed the Pending page icon is double clicked in the status bar or the File New or File Exit command 1s issued 103 Print Options Printer HP Laserlet 1200 Gerez PCL E Fage Orientation Portrait a C Landscape Margins 05 cm Fort Mame Times Hew Roman Size 10 gi Fe2p Cancel Printer Select one of the installed local or network printers
126. s and suggestions on further development of the program Reports on errors of library data possibly with the suggested new value and program bugs are also accepted Reprints of papers electronic or printed referring to XPS MultiQuant are highly appreciated Dr Miklos Mohai Institute of Materials and Environmental Chemistry Chemical Research Center Hungarian Academy of Sciences E mail mohai chemres hu Web _ http www chemres hu aki X MQpages X MQhome htm Fax 36 1 438 1147 If you find the program useful please refer to the following works of the author or to other ones if applicable in your papers XPS MultiQuant Multimodel XPS Quantification Software M Mohai Surf Interface Anal 36 828 2004 Correction for Surface Contaminations in XPS A Practical Approach M Mohai I Bertoti in ECAS A 95 Eds H J Mathieu B Reihl D Briggs p 675 John Willey amp Sons Chichester 1995 Calculation of Overlayer Thickness on Curved Surfaces Based on XPS Intensities M Mohai I Bertoti Surf Interface Anal 36 805 2004 Consideration of Two dimensional Surface Roughnesses in Quantitative XPS Analysis G Vars nyi G Mink K R e M Mohai Periodica Polytechnica 31 3 1987 XPS MultiQuant a step towards Expert Systems M Mohai Surf Interface Anal 38 640 2006 Calculation of Layer Thickness on Rough Surfaces by Polyhedral Model M Mohai Surf Interface Anal 40 710 2008 Calculation of Laye
127. s deposited by casting of polystyrene from benzene solution in subsequent steps The compositions of the samples atomic ratio were calculated with different contamination correction methods 35 Correction Difference method Sample treatment Si O C from SiO None As is 1 00 1 76 0 43 13 6 O plasma 1 00 2 02 0 20 1 0 Polymer 1 1 00 1 66 2 95 20 5 Polymer 2 1 00 1 49 3 81 34 2 Polymer 3 1 00 1 31 6 01 52 7 Evans As iS 1 00 1 97 0 44 1 5 O plasma 1 00 2 26 0 21 11 5 Polymer 1 1 00 1 85 3 07 8 1 Polymer 2 1 00 1 66 3 96 20 5 Polymer 3 1 00 1 46 6 25 37 0 Mohai AS iS 1 00 1 89 0 44 5 8 O plasma 1 00 2 08 0 20 3 8 Polymer 1 1 00 2 18 3 24 8 3 Polymer 2 1 00 2 04 4 26 2 0 Polymer 3 1 00 1 91 6 85 4 7 This example illustrates of application of the different contamination correction methods Try to change methods in the Contamination tab in the Parameters window and compare the results Cr O Si Cermet Film Cermet mqd Cr O Si cermet films are widely applied in microelectronics devices Such layers were prepared by RF sputtering of a Cr O Si target with a nominal atomic ratio of 1 1 1 onto thermally oxidised silicon wafers Oxygen balance Cr 0 SiO 0 10 20 30 40 50 60 lon bombardment time min 36 XP spectra of the characteristic lines Cr2p Si2p Ols Cls were recorded Ion bombardments were performed by 2 keV Ar ions Composition expressed in Oxide molar r
128. s installed to the computer this item is not available including shortcut The content of the Chart or Model Layout windows 1s printed immediately not spooled on a separate page the previously printed pending page 1s printed before the figure Exit Quits XPS MultiQuant Pending page is printed The current size and position of the main window is saved in the registry 67 Edit Menu AF Tul APL an d CERES LEE t e Edit View Tools Window Help Insert Row Fil Delete Rows Copy Table ASCI Ctrl C Paste Table MiS Word Clear Table Insert Row Inserts one empty row into the active input windows Elements or Intensity before the selected coloured line To select a row click the sequence number of elements or experiments The blank row should be filled immediately Delete Rows Deletes one or more selected rows from the active input windows Elements or Intensity Remainder lines are closed up To select rows click the sequence number of the first row then drag or SHIFT click the last one Copy Table gt Copies the content of the active window to the clipboard including row and column headers If the SHIFT key is pressed tables are copied without heading To paste data into an ASCII file e g into Notepad or Excel worksheet select the ASCII subcommand To paste into a Word document converting it to a table select the MS Word subcommand Data items are separated by TAB 9 character lines are terminated by CR
129. s quick how to instructions for some common tasks of XPS MultiQuant Consult the chapter Using of the Program for hints and the chapter Applied Methods for the theoretical background The Data wizard activated by the Tools Data wizard command may also give short step by step instructions online Setting and Saving Default Parameters l 2i On the View menu click Parameters Click the Cross Section tab Select the preferred cross section or sensitivity factor set Set Splitting and Scaling to None Click the IMFP tab Select the preferred inelastic mean free path correction method and fill the required not greyed parameters for common use Exponential method with an exponent between 0 5 and 0 7 is suggested Click the Angular tab Select the angular correction method Rei man if necessary Enter the angle between the electron analyser and the X ray source of the spectrometer Click the Transmission tab Select the transmission type of the spectrometer and enter the necessary data Click the Contamination tab Select the preferred contamination correction method for common use Mohai is suggested Click the Model tab Select the applied model for common use Homogeneous 1s suggested Set Multiline approach to None Click the Labels tab Select the labels routinely used e g Name or Time select also the measure units Click the General tab Select the routinely applied X ray excitation source If Other
130. s too large Calculating the transmission function with this value would cause overflow Parameter error s No transmission file specified The transmission type was set to File in the Transmission tab of the Parameters window but no file name was given in the Filename box Type the filename or use the Browse button Parameter error s The excitation analyser angle is invalid The Reilman type angular correction was selected but the analyser excitation angle is not set smaller than 0 or larger than 360 Enter the proper angle value of the applied spectrometer and save it as default Parameter error s The excitation energy is zero The Other excitation source was selected but the excitation energy is not set or zero Set the energy of the applied source Parameter error s The IMFP exponent must be between 0 and 2 The Exponential type IMFP correction method was selected but the value of the exponent is unrealistic Set other value usually between 0 5 and 0 9 or select another method Path not found or incorrect The path specified is either not existing or containing errors This error may also occur when an existing read only file is attempted to overwrite Printer error The printer is not ready out of paper or an error is occurred during printing or spooling Refine layer thickness values until Q sum is less than 50 The Autofit button is pressed but the Qsum value of the current parameters is greater than 50 Try to se
131. sample When the calculations are ready the Angle dependent experiment set checkbox can be selected to calculate the layer thickness based on all experiments 39 Surface Modified Carbon Nanotube C nanotube mqd Commercial thin multi wall carbon nanotubes with 9 5 nm external and 7 nm internal diameters were treated in a low pressure RF plasma in N2 flow Negative DC bias of 50 V was applied through the sample holder The upper layers of the tube wall were converted into N containing layer thus the Modified tube layer variant of the Layers on Nanotube model was applied to calculate the layer thickness The composition of the formed CN layer was selected as C3N2 based on measurements on similarly treated freshly cleaved highly oriented pyrolitic graphite sample The penetration depth of the N ions with 25 eV energy in carbon was calculated by the SRIM 2006 program The calculated depth sum of the projected ion range amp straggle is 0 6 nm which is very close to the layer thickness calculated from the intensity data of the XPS measurement 0 66 nm confirming by this the validity of the calculation 40 Applied Methods This chapter summarises all calculation methods and formulae built into the XPS MultiQuant All of the methods are described in details in the referred papers Homogeneous Model a Geet eee HP The intensity of the photoelectron line excited from the infinitesimal thin layer of an infin
132. so be edited on the General tab of the Parameters window Clear all data from title window Are you sure Confirm deleting the whole content of an input table Deleted data cannot be recovered Coverage should be between 0 and 1 The entered coverage value is less than zero or larger than one Enter the correct value Data file not found The specified data file cannot be found in the current folder Use the browsing feature of the Open dialog box to locate the file Division by zero occurred at fitting of parameters N Check model and refine initial data An attempt was made to divide a number by zero during the least square fitting of model parameters It may be caused by wrong initial data or that the model is not properly describe the measured data Division by zero occurred at model calculation N An attempt was made to divide a number by zero during calculation of intensity of structured models Do you want to save changed Notes text The text in the Notes window has been changed Select Yes to save changes No to discard changes or Cancel to continue editing To save notes permanently save the current XPS MultiQuant data file Do you want to save changed Transmission file The text in the transmission file editor window has been changed Select Yes to save changes No to discard changes or Cancel to continue editing Do you want to save your changes The content of the calculation has been changed since the last save Selec
133. splayed or enter the first letter of the class names e i p Enter the Bandgap energy values for each layer and the bulk for the Tanuma Powell Penn method only On the Tools menu click Model Calculate Valence Electrons for the TZanuma Powell Penn method only Click the Model window On the Tools menu click Model Calculate IMFPs 29 Notes The Density and Molecular weight rows are the same as in the Model window Calculating Layer Thickness oS OS On the View menu click Results On the View menu click Chart In the Layer Thickness window double click the number of experiment to be calculated In the Layer Calculation window double click the element symbol selected as basis element an element of the bulk is suggested Type the estimated thickness of the first layer and press ENTER Repeat with the remaining layers and optionally the coverage After the last ENTER the calculated intensity values are displayed and compared to the measured ones Repeat point 5 until reasonable Q um is achieved To reuse a previously typed thickness value press ENTER 7 Click the Autofit button 8 Click the OK button Notes To neglect an element during the automatic calculation double click the Omit column in the Model window an X appears To neglect a layer during the automatic calculation 1 e to keep the manually entered value double click the Link to row in the Model window until Fixed appears Definin
134. t feature was added New model types Uslands on Sphere Islands on Cylinder Multilayer repeated layer structures feature Enhanced data and model checking Several new messages New data file version 1 30 Reorganised Parameters window Colours of the program components are controlled by the system colours set in the Control Panel of the operating system The Data Wizard was added to help filling the tables Drag and drop file open The start bitmap and data file icons were merged into the application file 118 1 12 1 11 1 10 1 00 The development was migrated to Visual Basic 6 0 Minor printing and window handling errors were corrected The items of the atom location matrix in the Model window can be real numbers instead of integers New data file version 1 20 Title editing feature and new messages were added Pop up menu for editing cells in input windows was added Few minor bugs were corrected found by the author s four year old son The Islands on Plane model was added The intensity comparison graph was introduced to help layer thickness calculations User selectable source energy Improved help file and manual New data file version 1 12 Several minor bugs were corrected This was the first release of XPS MultiQuant It was developed using Microsoft Visual Basic Version 4 0 Professional Edition Predecessors MultiQuant A quantification program written for DOS It could calculate 33 experiments for DOS
135. t Yes to save changes No to discard changes or Cancel to continue work Element error s Invalid line notation at element symbol The line notation at the indicated element is either non existing e g 3z or the shell subshell and doublet items are not matching e g 3f 2p5 108 Element error s N element parameter s out of the expected range Some of the element data is out of the expected range e g density is greater than 22 5 or atomic mass 1s less than 1 etc Despite the warning calculation is continued Element error s Photoelectron lines chemical states mismatch at element symbol When more than one photoelectron lines are used to calculate the concentration of the same element Multiline approach and the chemical states are also distinguished each state must be present for each line E g the S2p 6 S2p 2 S2s 6 S2s 2 set is valid while the S2p 6 S2p 2 S2s total set 1s deficient Element error s Photoelectron line symbol line duplicated with identical chemical state at line N The same element with the same photoelectron line can be present only in different chemical states Delete one of the lines in the Element window or change one of the states Element symbol not found The specified element cannot be found in the library Check the element symbol for typing errors Enter atom locations initially The Tools Model Calculate IMFPs command was selected before entering the atom
136. t angles can be created or modified in the Polyhedron Editor window User can select each tilt angle in steps of 10 by moving the slider and enter the corresponding percentage ratio of its area projected to the base plane of the sample supporting the polyhedra 1 e the geometry correction factors The chart shows all the geometry correction factors as the function of tilt angles The figure on the left illustrates the direction of the incoming X ray and the ejected electron beams and also the angular position of the surface facets at the selected tilt angle The Area line represents the projected area of the current facet Tilt angle Shows the tilt angle selected by the slider Area Enter the percentage of the projected area corresponding to the surface elements with the selected tilt angle Numbers can be set in the textbox by clicking the arrow buttons or typing Clear Deletes all data of the polyhedron To recover accidentally deleted data click the Cancel button immediately 100 Normalize Normalize the entered area data to 100 sum Cancel Discards the last changes including clearing and closes Polyhedron Editor window OK Keeps the last changes normalizes data and closes Polyhedron Editor window Notes File Edit Format Help You can enter conrments and additional information for your calculations using the Notes window Wotes are stored within the EPS HultiQ uant data files Enter comments and add
137. t editor programs or with the internal editor of XPS MultiQuant Comment lines starting with mark are allowed at the beginning of the file The first non comment line is the type of the applied function It can be EXP for exponential POLY n for the polynomial function where n is the order of the polynomial which may vary between 0 and 6 NPL for the fourth order rational function developed at National Physical Laboratory UK 13 UNIFIT for the combined polynomial exponential function introduced at the University of Leipzig 14 and TABLE for the tabulated data Separate coefficient sets can be defined for different kinetic energy ranges The number of sets must be between 1 and 40 Coefficient sets are applied in the kinetic energy range from the given starting energy inclusive to the starting energy of the next range Subsequent lines of the file contain the kinetic energy and the list of coefficients 3 n 1 5 7 or 1 items respectively separated with commas or semicolons and optionally spaces The decimal separator must be period digit grouping is not allowed regardless of the locale settings For the NPL type rational function the two sets of coefficients for the numerator ao a4 and denominator 1 b b4 of equation 33 must be entered in two lines see the example below The bo coefficient which is always one must also be enumerated Coefficients of this type of function can be determined by the NPL XPS Intensity Cali
138. t symbol The number of basis atoms can be set in the Number textbox by clicking the arrow buttons or typing the number See chapter Normalisation of the Results for details If elements are present in more then one chemical state the different states of the same elements can be added by selecting the Merge chemical states check box This option is not available when any of the oxide result types 1s selected but in these cases the Oxygen balance is calculated and displayed in the last column of the window The Oxygen balance is the ratio of the measured and calculated required by the other elements at a given oxidation state and chemical formula oxygen concentrations The content of the header row chemical symbol line assignment chemical state oxide formula may vary according to the type of calculation multiline merged oxide etc Name U1s Us Sep 2 52p 6 523 2 52s 6 Nals Na p al 1 Thiosulphate 21 4 0 amA e Ma rd 14 5 14 3 42 3 D 5 Ha 3 00 2 00 2 00 80 Chart Atomic 20 30 Time min The results of the quantification can be displayed in graphical forms as well This window interacts with the Composition or the Layer Thickness windows X axis is set as initially selected in the Labels tab of the Parameters window and Y axis as the result type selected in the Composition or the Layer Thickness windows When settings are changed in the latter windows it will be reflected in the Chart window immediately o
139. ted areas and the original surface is quite different at various sample tilt angles 56 Layers on Nanotube Model d SAY _ CN Cos The description of intensity of photoelectrons emitted from cylindrical surfaces covered by overlayers despite the simplicity of the shape cannot be applied directly for nanotubes 20 In this latter case the diameter of the nanotubes and the thickness of the tube wall are commensurable with the thickness of the layers This means that there is no bulk like 1 e infinitely thick material the electrons are emitted from the bottom part of the nanotubes and they can emerged from several rows of tubes and passing through the top one The algorithm of the calculation used for the cylindrical model cannot be applied either In that case the cross section of the tube is divided into segments of equal angles When this division is applied to nanotubes the matching effective thickness values originated from the layers and the tube wall read at the middle angle of segments are misaligned as shown in the next figure and would give erroneous results Thus tubes must be divided into segments of equal width instead of equal angle 57 The size of the tube cannot be neglected as well Both the outer R and inner r radii must be known They are usually determined by transmission electron microscopy For nanofibres the inner radius may be set to zero In case of carbon nanotubes t
140. ters Model Homogeneous Multiline approach None Excitation Mg K 1253 6 eV Cross sections Scofield IMFP correction method Seah Dench material class Inorganic density 7 80 g cm mean atomic w Auto Angular correction method Reilman analyser excitation 65 0 Transmission type Exponential exponent 0 8 Contamination correction method None Elements Line State B E Cross s Asymm At w Val Ox Fe 2p3 707 0 2 0390 1 4510 55 850 3 3 Cr 2p 574 0 2 3400 1 4590 52 000 3 3 O Ils 531 0 0 6240 2 0000 16 000 2 0 N Ils 398 0 0 3840 2 0000 14 010 5 5 C Ils 285 0 0 2250 2 0000 12 010 4 2 Intensity Name Time min Fe Cr O N C 1 PN 11 l 29722 2682 23486 1100 8745 2 PN 11 2 37732 3301 30824 1237 4382 3 QNC 57 50 63022 1561 15708 1914 4937 4 QNC 57 80 82577 1472 16720 2558 3112 Atomic Name Time min Fe Cr O N C 1 PN 11 l 14 4 i 38 2 3 1 43 1 2 PN 11 2 19 2 1 6 52 9 3 6 22 8 3 QNC 57 50 35 2 0 8 29 6 6 2 28 2 4 QNC 57 80 44 2 0 7 30 2 7 9 17 0 Notes Plasma nitrocarburised steel PN samples PI3 nitrocarburised steel QNC samples To produce high quality graphs e g depth profiles export the results into Excel Origin or any other charting program 18 Application of Structured Models When the surface of the sample is covered by one or more overlayers and you know or at least assume the composition of the layers the thickness of the layers can be estimated from the photoelectron intensity ratios The shap
141. tification data set from overwriting by an accidental library lookup If lookup is not enabled a warning message is displayed when the Tools Library Lookup command issued Cross Section Tab Contamination Model Labels General Cross section l IMFF Angular Transmission Data set Evans Type Experimental cross sections Splitting Theoretical data Scaling None 7 Pririt Cancel Apply OF Data set Select the cross section or sensitivity factor set None none of the library sets are looked up and no pre treatment 1s used Scofield theoretical relative differential cross sections separate sets for Mg Ka and Al Ka excitations Evans experimentally based relative differential cross sections for Mg Ka excitation with pre treatment Wagner experimentally based relative sensitivity factors for Mg Ka and Al Ka excitation with pre treatment Nefedov experimentally based relative sensitivity factors for Al Ka excitation 89 Type Displays the type of the above data set theoretical or experimental cross section experimental sensitivity factor user defined Splitting Select the method of splitting of experimental cross sections of doublet lines into components None no splitting is applied Theoretical data doublets are split by the ratio of the corresponding theoretical cross section data Nominal values doublets are split by the the nominal ratio values 1 2 2 3 and 3 4 for p d and f lines respective
142. time the file becomes the current file and its name is displayed in the status bar Then you can save the data into the current file by the File Save command or by the CTRL S shortcut Saved files can be loaded by the File Open command You can open files on mapped network drives as well but you must have writing permission to that drive full access type Files can also be opened by drag and drop the data file from the Windows Explorer to the main window of XPS MultiQuant Results can be printed on any local or network printer connected to your computer Perform the File Print command To start with press the Options button and select the required printer page orientation font type and size Return to the Print window select items to be printed and press the Print button to print Results are printed with the last selected settings type basis element merging etc Pages are spooled and printed only when physically full A small page icon is appearing in the status bar indicating the pending page To print the pending unfinished page press the Eject Page button in the Print window or double click the page icon Settings of the Print and Print Options windows are also stored in the registry when File Save Defaults executed You can also print the content of any window immediately Just select the File Print Current command or press CTRL P to print the content of the active window The logically connecting parts of the printout like head
143. tion of the spectrometer e The typical labels you want to attach to the experiments Every setting can be overwritten later as necessary When all the parameters are set select the File Save Defaults command to store your preferred settings in the registry Entering and Editing Input Data First of all specify the elements you want to use in the calculation Click the File New or View Elements command to invoke the Elements window and fill the table You can navigate in the table with the arrow keys or mouse clicks see chapter Status Bar Type the symbol of the elements and the name of the selected lines as shown by the following examples Transition Symbol Line W4f doublet W 4f W4f7 2 component W 4f7 Cu2p doublet Cu 2p Cu2p1 2 component CU 2pl Cu2p3 2 component cu 2p3 2 13 The program accepts the element symbols also with improper capitalisation and transition names with or without the 2 tag as well You can enter the line notations simply by double clicking the cells The program inserts the notations of the most frequently used usually the most intensive lines in the 1s 2p 3d 4d 4f order After selecting the elements click the Tool Library Lookup command to fill all the fields left of the table from the library of XPS MultiQuant Of course you can type in your own data manually or you can overwrite any particular fields filled from the library Use the State column to distinguish between di
144. tivity factor Fi 0 L 9 B T 49 The number of atoms per unit volume Jj is calculated by the following formula p ni 50 where n is the stoichiometric coefficient of atom i M is the molecular weight and p is the density in gcm Molecular weight and density values should be supplied for each layer also stoichiometric coefficients and explicit IMFP values for each layer and element 1 e kinetic energy Contamination correction can be implemented by defining an explicit contaminant layer 1 to 5 layers and the bulk can be defined in the program but for materials with repeated structure the defined layer system can be multiplied also by a factor from 1 to 5 The calculated intensity ratios can be fitted to the experimental ones either manually by interactive iterations or automatically by least square fitting procedure To help finding the best fit of the intensity the difference Diff between the calculated Zear and measured Ions Intensity and the sum of the squares of the differences Qsum are also calculated Diff cale lobs 499 51 obs 2 Qsum 2 calc lobs 52 i where the 7 index stands for the elements Diff is displayed only when smaller than 100 Graphic tools are also available see chapter Model in Program References The actual number of the applied equations calculating intensity depends on the number and distribution of the elements in the layers For a definite system w
145. tted element can be brought back by double clicking again When ratio type results are selected the basis element of the calculation can be set by double clicks as well If the concentration of the selected basis element is zero for some experiments the previous non zero basis is kept for these experiments The number of atoms of the basis element can be set in the Number textbox by clicking the arrow buttons If you enter an element in more then one chemical state the different states of the same element can be summed up by selecting the Merge chemical states check box In this case the double clicks the element symbols will not work This option is not available when oxide type results are selected because it makes no sense to add the quantity of different compounds In these latter cases the Oxygen balance is calculated and displayed in the last column of the window which shows the ratio of measured and calculated required by the applied chemical formula oxygen If it is less than 1 the surface is deficient in oxygen if it is greater than 1 there is oxygen surplus Results can be demonstrated in graphical form in the Chart window View Chart command It co operates with the Composition window Results are presented as line chart or as pie chart if only one experiment entered When you change the Composition window it 1s reflected in the Chart window immediately or after clicking it The X category axis of the line chart is taken fr
146. up Menu Model Layout window Copy Figure Colours Legend This pop up menu activated by a right mouse click is available in the Model Layout window Copy Figure Copies the content of the Model Layout window to the clipboard in device independent bitmap DIB format To obtain the best quality higher resolution picture adjust the size of the Model Layout window before copying Colours Switches on or off the colours of the model layout figure Legend Switches on or off the legend text layer names of the model layout figure 76 Windows Users enter input data and also get results in different windows Windows can be invoked by the View menu command Enter data into the boxes select from the possibilities of the drop down lists and set options by selecting check boxes or option buttons When large amount of data are required fill out the tables Users can navigate in the tables by the arrow keys or mouse clicks The BACKSPACE key deletes the last character of a cell while the DELETE key deletes the whole content of a cell Where a number is expected in a table two numbers connected with an arithmetic operator can also be used instead of it The numbers may have sign decimal separator and exponent with optional sign Windows can be repositioned and resized within the main window XPS MultiQuant adjusts the optimal size of each window when they are opened and resize them when it is necessary e g elements are inserted or
147. ure of the Transmission Files and correct the file Illegal data file header The header of the specified data file is not valid The file should be damaged or the file is not an XPS MultiQuant data file even the extension is mqd Illegal or damaged library file header The header of the library is not valid The file should be damaged or the file is not the valid XPS MultiQuant library file N IMFP amp Contamination parameter s out of the expected range Some of the inelastic mean free path or contamination correction data is out of the expected range e g density is greater than 22 5 Despite the warning calculation is continued Improper IMFP method selected The current IMFP correction method cannot be applied for the selected quantification model Incompatible data file version The version of the data file is too old This version is no more supported Incompatible library Library version should be N The version of the library is too old Libraries of the different versions are not compatible Use the library supplied with the program Incorrect dataset Intensity always 0 No valid experimental intensity data was found at the layer thickness calculation Check or enter the content of the Intensity window Intensity data set is not empty Do you want to overwrite The Intensity Simulation window was invoked but some intensity data are larger than zero either measured or simulated Simulation may overwrite the selected experim
148. y E calculated If the Chart window is displayed when the Layer Calculation window is invoked the content of the Chart window is changed to a bar graph as shown above The graph compares the measured and calculated relative intensity values of the elements This feature helps to find the optimum of the layer thickness and coverage values Adjust the size and position of the Chart window as convenient before the Layer Calculation window is invoked Model Layout 86 The Model Layout window displays the geometric scheme of the applied quantification model Keep in mind that it gives a graphical representation of the results of the structured model calculations only and not a realistic picture of the examined sample The various information represented graphically in the Model Layout window are summarised in the next figure HSS SS4 Up r ROR E6666 A ee eee Wp a The thickness of the drawn layers d d2 are proportional to each other but in case of the spherical or cylindrical models the layers are oversized relative to the bulk For the Homogeneous model the thickness of the contaminant c is proportional to the contamination correction factor In case of the s and type models the widths of the island and non island parts are proportional to the coverage O In case of the Layers on Nanotube model the inner and outer radii of the tube r R are proportional to each other but not to the layer thickness When t
149. y deleted remove the files and registry entries listed in the next chapter If you are not familiar with the registry editing do not tamper it ask your system manager After improper registry manipulation your computer may become non functional If you have programs using the same shared programming components the files installed into the Windows System folder do not remove them Technical Notes Files Installed File Folder Description XMQ exe Program Files XMQ XPS MultiQuant application XMQ lib Program Files XMQ XPS MultiQuant Library XMQ chm Program Files XMQ XPS MultiQuant Help mtr Program Files XMQ Transmission files Stounst log Program Files XMQ Uninstall log file Al Layers mqd Al Oxide mqd Cermet mqd C nanotube mqd Contact mqd CuAgAu mqd NaCl multiline mqd NaCl scaling mqd S1 ARXPS mqd S1N powder mqd S102 contam mqd S102 simulation mqd Si wafer mqd Steel mqd Cermet mat S1 S102 CH mat Cermet mqx CuAgAu mtr Exponential mtr Polynom mtr Rational mtr Combined mtr ContactProfile xls Steel Document doc ComCtl32 0cx Comdlg32 0cx Graph32 0cx Gsw32 exe Gswag32 dll Gswdll32 dll MSflxgrd32 0cx MSvbvm60 dll Sysinfo ocx Tabctl32 0cx Stounst exe Program Files XMQ Samples Program Files XMQ Samples Program Files XMQ Samples Program Files XMQ Samples Program Files XMQ Samples Program Files XMQ Samples Program Files XMQ Samples Program Files XMQ Samples Program Files XMQ Samples Program Files XMQ
150. y the Tools Simulation command If the intensity data set is not completely empty 1 e all zero a message warns the user that further actions may destroy the previously entered either experimental or simulated intensity data Select an experiment to store simulated intensity New experiments can be added only to the end of the data set but any previously calculated experiment can be recalculated later Enter the thickness of the layers and optionally the coverage for the island type models and press the Calculate button The inverse of the corrections selected in the Parameters window cross section IMFP transmission angle are applied Surface contamination can be implemented by defining a carbonaceous top layer You can assign a name which is stored as the Name label of the selected experiment If it were empty the word Simulated is inserted These automatically entered labels can be changed later in the ntensity window Other labels like Time Tilt etc can also be added To calculate angle dependent experiments enter the tilt angle values for each experiment as Tilt labels in the ntensity window before the simulation and enter any number as intensity at least into each experiment unless the automatic counting will delete it If you want to create an angle dependent set do not select the Angle dependent experiment set checkbox in the Model tab of the Parameters window during the simulation For the first time it seems
151. ymmetry parameter and is the angle between the excitation source and the analyser entrance slit Correction for Elastic Scattering This correction is calculated by the method of Ebel et al 5 6 using equation 12 B B 1 0205 exp 0 0093356 A 12 where f is the effective asymmetry parameter and 4 is the atomic weight for elements or the effective atomic weight for compounds 1 Aef gt XA 13 eff 100 JX x 1s the atomic percent of element j First x is calculated without correction The effect of this factor is usually about a few percent or less 43 Inelastic Mean Free Path IMFP Beside the known and explicitly given inelastic mean free path values of the material examined the IMFP can be also calculated by several methods An exponential function can be used which is proportional to IMFP oc E 14 where is the kinetic energy eV The exponent a being usually between 0 5 and 0 9 can be freely selected by the user Jablonski 7 uses similar approximation with pre set exponents for three material classes 0 7283 0 7234 and 0 7665 for elements inorganic materials polymers respectively Seah and Dench 8 also calculate the IMFP for the three above classes using equations 15 17 for elements inorganic materials and polymers respectively N oF 0 41 aE monolayers 15 r 0 72 aE monolayers 16 n 0 11 E4 mg m7 17 where is the kinetic energy e

XPS MultiQuant User`s Manual - The Molecular Materials Research

Contents

Download Pdf Manuals

Related Search

Related Contents