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1. H PAR E lt n gt LIN BREA lt n gt PAR BREA lt n gt LIN PDEP lt n gt PAR PDEP lt n gt GAMMA 0 lt n gt GAMMA E lt n gt LIN PCT PAR PCT LIN CLDE PAR CLDE COLUMN lt n gt TABLE lt c gt MATERIAL lt c gt SILICON OXIDE OXYNITRI NITRIDE POLYSILI AMBIENT D 0 lt n gt D E lt n gt VC lt c gt HENRY CO lt n gt THETA lt n gt MATERIA lt c gt SILICON OXIDE OXYNITR NITRIDE POLYSIL AMBIENT SEG 0 lt n gt SEG E lt n gt TRANS 0O lt n gt TRANS E lt n gt ALPHA lt n gt STRESS D VR lt c gt VT lt ce gt VD lt c gt VDLIM lt n gt INITIAL lt n gt SPREAD lt n gt MASK EDG lt n gt ERF Q lt n gt ERF DELT lt n gt ERF LBB lt c gt ERF H lt c gt NIT THIC lt n gt CLEAR TEMPERAT lt c gt CM SEC Parameter Type Definition DRYO2 logical Specifies that the pressure chlorine percentage and flows of oxidizing and non oxidizing species are associated with the dry oxygen ambient Default false 3 196 Confidential and Proprietary S4 1999 2 TSUPREM 4 User s Manual Parameter WETO2 STEAM INERT F H20 F H2 S4 1999 2 Type logical logical logical logical logical logical logical logical number number number AMBIENT Definition Specifies that the pressure chlorine percentage and flows of oxidizing and non oxidizin
2. Synonyms PAR L 0 The activation energy in the expression for the parabolic oxidation rate for tem peratures below the temperature breakpoint set by PAR BREA Units electron volts Default current value for this oxidant Synonyms PAR L E The pre exponential constant in the expression for the parabolic oxidation rate for temperatures above the temperature breakpoint set by PAR BREA Units microns min or cm sec Default current value for this oxidant Synonyms PAR H 0 The activation energy in the expression for the parabolic oxidation rate for tem peratures above the temperature breakpoint set by PAR BREA Units electron volts Default current value for this oxidant Synonyms PAR H E Confidential and Proprietary 3 199 Section 3 5 Models and Coefficients TSUPREM 4 User s Manual Parameter LIN BREA PAR BREA LIN PDEP PAR PDEP GAMMA 0 GAMMA E LIN PCT PAR PCT LIN CLDE PAR CLDE 3 200 Type number number number number number number logical logical logical logical Definition The temperature breakpoint at which the temperature dependence of the linear oxidation rate changes Units degrees Celsius Default current value for this oxidant Synonyms L BREAK The temperature breakpoint at which the temperature dependence of the para bolic oxidation rate changes Units degrees Celsius Default current value for this oxidant Synonyms P BREAK
3. model and current point defect model are saved in TSUPREM 4 structure files and are automatically restored when the file is read There is no need to respecify these parameters after reading in a structure This does not apply to versions of TSUPREM 4 prior to version 9035 versions older than 9035 only saved the sub strate orientation Confidential and Proprietary S4 1999 2 TSUPREM 4 User s Manual Older Versions LOADF ILE Files saved with older versions of TSUPREM 4 can be loaded by newer versions of the program Files saved with version 5 1 and newer of TSUPREM 4 cannot be read by older versions of the program In versions of TSUPREM 4 prior to version 5 1 the STRUCTURE statement is used to load structure files Starting with version 5 1 the LOADFILE statement should be used instead The IN FILE SCALE FLIP Y and DEPICT parame ters are still accepted on the STRUCTURE statement however for compatibility with older TSUPREM 4 input files User Defined Materials and Impurities Any user defined materials and impurities referenced in a structure file should be defined before the file is loaded If a file containing undefined materials or impuri ties is loaded a warning is issued for each undefined material or impurity encoun tered The material or impurity is defined but its properties are not set Further simulation using the material or impurity may fail unless the properties are set Taurus Lithography Files
4. number number number number number number number AMBIENT Definition The characteristic length in the expression for the thin oxide growth rate parameter Units microns Default current value for this orientation and oxidant The pre exponential constant in the expression for the linear oxidation rate for temperatures below the temperature breakpoint set by LIN BREA Units microns min or cm sec Default current value for this orientation and oxidant Synonyms LIN L 0 The activation energy in the expression for the linear oxidation rate for tempera tures below the temperature breakpoint set by LIN BREA Units electron volts Default current value for this orientation and oxidant Synonyms LIN L E The pre exponential constant in the expression for the linear oxidation rate for temperatures above the temperature breakpoint set by LIN BREA Units microns min or cm sec Default current value for this orientation and oxidant Synonyms LIN H 0 The activation energy in the expression for the linear oxidation rate for tempera tures above the temperature breakpoint set by LIN BREA Units electron volts Default current value for this orientation and oxidant Synonyms LIN H E The pre exponential constant in the expression for the parabolic oxidation rate for temperatures below the temperature breakpoint set by PAR BREA Units microns min or cm sec Default current value for this oxidant
5. with a structure having an unmasked initial oxide thickness other than INITIAL Confidential and Proprietary 3 205 Section 3 5 Models and Coefficients ERFG Model VERTICAL Model COMPRESS Model VISCOELA Model VISCOUS Model 3 206 The ERFG model is by Guillemot et al IEEE Transactions on Electron Devices ED 34 May 1987 The bird s beak shape and nitride lifting are functions of pro cess conditions The ERFG model is controlled by the ERF Q ERF DELT ERF LBB ERF H NIT THIC and INITIAL parameters The above com ments regarding INITIAL apply the ERFG model as well The ERF1 and ERF2 models use the two shapes derived by Guillemot et al the ERFG model chooses between them based on process conditions The VERTICAL model has no fitting parameters but is only accurate when the growth is approximately vertical within about 30 of vertical The VERTICAL model does not simulate oxidation of polysilicon The VERTICAL model can be used for oxidation of uniform substrates with arbitrary initial oxide thicknesses and for approximating nonrecessed LOCOS processes Concentra tion dependence of the oxidation rate is included in the VERTICAL model The COMPRESS model simulates the viscous flow of the oxide in two dimensions It uses simple three nodes per triangle elements for speed but must allow some compressibility as a consequence It is more accurate than the VERTICAL model but requires more computer time It
6. 4 User s Manual DIFFUSION Parameter Type Definition STEAM logical Specifies that the ambient gas is steam Default false INERT logical Specifies that the ambient gas is inert Default true Synonyms NEUTRAL NITROGEN ARGON AMB 1 logical Specifies that the ambient gas is ambient number one Ambient number one is defined by the user with the AMBIENT statement Default false AMB 2 logical Specifies that the ambient gas is ambient number two Ambient number two is defined by the user with the AMBIENT statement Default false AMB 3 logical Specifies that the ambient gas is ambient number three Ambient number three is defined by the user with the AMBIENT statement Default false AMB 4 logical Specifies that the ambient gas is ambient number four Ambient number four is defined by the user with the AMBIENT statement Default false AMB 5 logical Specifies that the ambient gas is ambient number five Ambient number five is defined by the user with the AMBIENT statement Default false F 02 number The flow of O2 associated with the ambient gas If H2 is also present the O2 and H2 is assumed to react completely to form H20 The flows of O2 and H2 are reduced and the flow of H20 is increased Units none Default 0 0 F H20 number The flow of H20 associated with the ambient gas If O2 and H2 are also present the O2 and H2 are assumed to react completely to form H20 The flows of O2 and H2 are reduced and the flow of H20 is
7. Examples S4 1999 2 Files produced by Taurus Lithography do not contain the complete mesh and solution information required by TSUPREM 4 Rather they are used to update an existing structure with the results of a Taurus Lithography simulation Thus the usual sequence for interfacing with Taurus Lithography is 1 Generate a structure in TSUPREM 4 either from an initial mesh definition or by reading a saved structure 2 Save the structure in both TSUPREM 4 and Taurus Lithography formats This requires two SAVEFILE statements and two output files 3 Use Taurus Lithography to process the structure starting with the saved Taurus Lithography format file Save the results in a new Taurus Lithogra phy format file 4 Read the saved TSUPREM 4 format file into TSUPREM 4 with an INITIALIZE or LOADFILE statement 5 Read the new Taurus Lithography format file into TSUPREM 4 with a LOADFILE statement 1 The following statement reads in a previously saved structure from file savestr LOADFILE IN FILE savestr Confidential and Proprietary 3 63 Section 3 2 Device Structure Specification TSUPREM 4 User s Manual 3 64 2 The following statements save a structure to be processed further with Tau rus Lithography SAVEFILE OUT FILE STRTS4 SAVEFILE OUT FILE STRTODEP DEPICT Taurus Lithography can read the file STRTODEP The structure file STRTS4 is needed when reading the results produced by Taurus Lithography If Tau rus Lit
8. If TEMPERAT is not specified the last processing temperature is used If the last process step ended with a ramp to a low temperature you may need to specify a higher value of TEMPERAT in order to obtain realistic levels of dopant activation Confidential and Proprietary S4 1999 2 TSUPREM 4 User s Manual Examples S4 1999 2 The logarithm base 10 of the arsenic concentration is evaluated with SELECT Z 1lo0g10 Arsenic The phosphorus concentration minus a constant profile of 5x10 is evaluated with SELECT Z Phosphorus 5 0e14 The difference between the phosphorus concentration and an analytic profile is evaluated with SELECT Z phos 1 0e18 exp y y The excess vacancy interstitial product is evaluated with SELECT Z inter vacan ci star cv star The diffusivity in cm sec of boron at each point in the structure is evaluated with SELECT Z diffusivity Boron Note that when the PD TRANS or PD FULL model for point defects is used the diffusivity can be different at each point in the structure and may vary with time The following statements print junction depths SELECT Z doping PRINT LAYERS X V 0 The PRINT LAYERS statement assumes that a new layer begins whenever the selected value net doping in this case changes sign The following statements print the thicknesses of material layers SELECT Z 1 0 PRINT LAYERS X V 0 The SELECT statement specifies a constant value
9. MATERIA SILICON OXIDE OXYNITR NITRIDE POLYSIL AMBIENT SEG 0 3 202 Type number character number number character logical logical logical logical logical logical number Definition The activation energy in the expression for the diffusion of oxidant in the speci fied material Units electron volts Default current value for this oxidant and material Synonyms DIFF E A table of activation volumes as a function of temperature for the dependence of material viscosity on shear stress for the specified material and oxidizing species 02 or H20 Entries in the table correspond to temperatures given by the TEMPERAT parameter see text Units A Default the current value initially 300 The solubility of oxidant in the specified material at one atmosphere Units atoms cm atm Default current value for this oxidant and material The number of oxide molecules per cubic centimeter of oxide Units atoms cm Default current value The specified coefficients apply to the interface between the other specified material and this named material Default none The specified coefficients apply to the interface between the specified material and silicon Default True if no other second material is specified The specified coefficients apply to the interface between the specified material and oxide Default false The specified coefficients apply to the interface betwe
10. OXIDE OXYNITRI NITRIDE POLYSILI ALUMINUM PHOTORES POSITIVE NEGATIVE IMPURITY lt c gt I CONC lt n gt I RESIST lt n gt ANTIMONY lt n gt ARSENIC lt n gt BORON lt n gt PHOSPHOR lt n gt CONCENTR RESISTIV THICKNES lt n gt SPACES lt n gt DY lt n gt YDY lt n gt ARC SPAC lt n gt TEMPERAT lt n gt GSZ LIN TOPOGRAP lt c gt Definition character The name of the material to be deposited logical logical logical logical logical logical logical logical logical Default none Deposit silicon Default false Deposit oxide Default false Deposit oxynitride Default false Deposit nitride Default false Deposit polysilicon Default false Deposit aluminum Default false Deposit photoresist Default false Specifies that the deposited photoresist and all other photoresist in the struc ture is positive i e that the DEVELOP statement removes exposed photoresist while leaving unexposed photoresist Default true unless NEGATIVE is specified Specifies that the deposited photoresist and all other photoresist in the struc ture is negative i e that the DEVELOP statement removes unexposed photo resist while leaving exposed photoresist Default false Confidential and Proprietary S4 1999 2 TSUPREM 4 User s Manual Lz EPOSITION Parameter Type Definition IMPURITY character The name of the impur
11. TSUPREM 4 structure files and are automatically restored when the file is read There is no need to respecify these parameters after reading in a structure This does not apply to versions of TSUPREM 4 prior to version 9035 versions older than 9035 only saved the sub strate orientation Older Versions Files saved with older versions of TSUPREM 4 can be loaded by newer versions of the program Files saved with version 5 1 and newer of TSUPREM 4 cannot be read by older versions of the program In versions of TSUPREM 4 prior to version 5 1 the STRUCTURE statement is used to load structure files Starting with version 5 1 the LOADFILE statement should be used instead The IN FILE SCALE FLIP Y and DEPICT parame ters are still accepted on the STRUCTURE statement however for compatibility with older TSUPREM 4 input files Effective in version 5 2 of TSUPREM 4 active impurity concentrations are saved by default in TSUPREM 4 structure files Structure files without the active impurity concentrations can be produced by specifying ACTIVE on the SAVEFILE statement This is necessary if the structure files are to be read by older prior to 5 2 versions of TSUPREM 4 or by other programs that cannot accept the active concentration information TIF Files The TIF parameter specifies that the file should be saved as a TIF Technology Interchange Format file The version of TIF can be specified with the TIF VERS parameter newer products
12. Units microns Default X MIN X MAX 2 if FULL DEV is specified not applicable if HALF DEV is specified The x coordinate of the left edge of the MINIMOS 5 simulation region Units microns Default left edge of the TSUPREM 4 simulation region Confidential and Proprietary S4 1999 2 TSUPREM 4 User s Manual SAVEFILE Parameter Type Definition X MAX number The x coordinate of the right edge of the MINIMOS 5 simulation region Units microns Default right edge of the TSUPREM 4 simulation region Y MIN number The y coordinate of the top edge of the MINIMOS 5 simulation region MINIMOS 5 interprets this coordinate as the gate oxide silicon interface Units microns Default 0 0 Y MAX number The y coordinate of the bottom edge of the MINIMOS 5 simulation region Units microns Default bottom edge of the TSUPREM 4 simulation region DX MIN number The minimum spacing in the x direction used to specify the doping profiles in the output file Units microns Default min X MAX X MIN 80 0 01 DY MIN number The minimum spacing in the y direction used to specify the doping profiles in the output file Units microns Default min MAX Y MIN 80 0 01 WAVE logical Specifies that the output file is a formatted file in Wavefront Technologies wave file format These files can be read by Wavefront Technologies Data Visualizer program Default false ACTIVE logical Specifies that active impurity conce
13. at most eight rows in a table and each row corresponds to one chlorine percentage At most eight values can be defined with this parameter Units percent or none Default none The specified coefficients apply to the named material or to the interface between the named material and some other material Default none The specified coefficients apply to silicon or the interface between silicon and some other material Default false The specified coefficients apply to oxide or the interface between oxide and some other material Default true if no other first material is specified The specified coefficients apply to oxynitride or the interface between oxyni tride and some other material Default false The specified coefficients apply to nitride or the interface between nitride and some other material Default false The specified coefficients apply to polysilicon or the interface between polysili con and some other material Default false The specified coefficients apply to gas or the interface between gas and some other material Default false Synonyms GAS The pre exponential constant in the expression for the diffusivity of oxidant in the specified material Units microns min or cm sec Default current value for this oxidant and material Synonyms DIFF 0 Confidential and Proprietary 3 201 Section 3 5 Models and Coefficients TSUPREM 4 User s Manual Parameter D E ve HENRY CO THETA
14. boundary of the device structure The quantity to be printed must be specified on a SELECT statement preceding the PRINT 1D statement The SPOT parameter finds all points along the specified path at which the selected quantity equals the specified value Layers If LAYERS is specified the integral of the selected quantity over each layer is printed The integration is along the path defined by the X VALUE Y VALUE or interface specification Layers are delimited by those points along the path where the material type changes or the sign of the selected quantity changes If a cross section passes out a structure into the ambient and then re enters the structure the ambient layer may be omitted from the LAYERS output Interface Values The values along the interface between two materials depend on the order in which the materials are specified Thus SILICON OXIDE and OXIDE SILICON print values at the same interface but the first prints the val ues in the silicon while the second prints the values in the oxide Values along an interface are sorted by their x coordinates The values printed may not be in order if there are vertical or reentrant interfaces or if the structure con tains more than one interface between the specified materials Examples 1 The following statements print the boron concentration at x 1 0 micron between the top of the mesh and y 3 0 microns SELECT Z Boron PRINT 1D X VAL 1 0 X MAX 3 0 2 Th
15. data read by the IN FILE parameter is as follows Data of X axis X SCALE x Data of X COLUMN or X AXIS X SHIFT Data of Y axis Y SCALE x Data of Y COLUMN or Y AXIS Y SHIFT Examples 1 The following statement clears the screen draws a set of axes and plots a vertical cross section at x 1 0 micron PLOT 1D X V 1 0 SYMB 1 CURVE Symbol 1 a small square is drawn at each data point the line through the data points is suppressed 2 The following statement plots a cross section at x 2 0 microns on the previ ous set of axes without clearing the screen PLOT 1D X V 2 0 AXES CLEAR LINE TYP 2 COLOR 3 A line consisting of short dashes is used and appears in color 3 on color dis plays S4 1999 2 Confidential and Proprietary 3 135 Section 3 4 Output TSUPREM 4 User s Manual LABEL The LABEL statement is used to add a label to a plot LABEL X lt n gt Y lt n gt CM X CLICK lt c gt Y CLICK lt c gt SIZE lt n gt COLOR lt n gt LABEL lt c gt LEFT CENTER RIGHT LINE TYP lt n gt C LINE lt n gt LENGTH lt n gt SYMBOL lt n gt C SYMBOL lt n gt RECTANGL C RECTAN lt n gt W RECTAN lt n gt H RECTAN lt n gt Parameter Type Definition X number The horizontal location corresponding to the left end center or right end of the character string depending on whether LEFT CENTER or RIGHT is specified If the CM parameter
16. entries are added or changed by specifying lists of values with VC VD VR or VT and temperatures with TEMPERAT The portion of the table spanned by the specified temperatures is replaced by the specified values the number of values must be the same as the number of temperatures and the temperatures must be given in order lowest to highest The CLEAR parameter is used to clear a table before setting any values For example the statement AMBIENT O2 CLEAR VD 40 50 60 TEMP 800 900 1050 removes any old values from the table of VD vs temperature for O2 and adds three new values The statement AMBIENT 02 VD 55 75 TEMP 900 1100 would then replace the values at 900 C and 1050 C with new values at 900 C and 1100 C If no oxidizing species is specified the values apply to ambients containing either O or H20 The material should be specified when setting VC if no material is specified OXIDE is assumed If V COMPAT on the OPTION statement is less than 6 6 the specified values of the activation volumes apply to oxide in all ambi ents including inert ambients An Arrhenius interpolation is used between values in the table For temperatures outside the range of the table the nearest value is used S4 1999 2 Confidential and Proprietary 3 207 Section 3 5 Models and Coefficients TSUPREM 4 User s Manual Coefficients Chlorine Examples 3 208 The diffusion and segregation coefficients can be used to model oxidant d
17. is specified then this parameter specifies a location in centi meters relative to the left edge of the graphics viewport Otherwise this parame ter specifies the location in axis units along the horizontal axis Units cm or horizontal axis units Default none Y number The vertical location corresponding to the bottom of the character string If the CM parameter is specified then this parameter specifies a location in centimeters relative to the bottom edge of the graphics viewport Otherwise this parameter specifies the location in axis units along the vertical axis Units cm or vertical axis units Default none CM logical Specifies that the X and Y parameters are locations in centimeters relative to the lower left edge of the graphics viewport Default false X CLICK character The variable name to store the x coordinate of the position at which a mouse is clicked Units horizontal axis units Default none Y CLICK character The variable name to store the y coordinate of the position at which a mouse is clicked Units cm or vertical axis units Default none 3 148 Confidential and Proprietary S4 1999 2 TSUPREM 4 User s Manual Parameter SIZE COLOR LABEL LEFT CENTER RIGHT LINE TYP C LINE LENGTH S4 1999 2 Type number number character logical logical logical number number number LABEL Definition The height of the characters in the character string and the defa
18. silicon at the interface with the other specified material Default false OXIDE logical Print values in oxide at the interface with the other specified material Default false OXYNITRI logical Print values in oxynitride at the interface with the other specified material Default false NITRIDE logical Print values in nitride at the interface with the other specified material Default false POLYSILI logical Print values in polysilicon at the interface with the other specified material Default false PHOTORES logical Print values in photoresist at the interface with the other specified material Default false 3 124 Confidential and Proprietary S4 1999 2 TSUPREM 4 User s Manual PRINT 1D Parameter Type Definition ALUMINUM logical Print values in aluminum at the interface with the other specified material Default false MATERIA character Print values in the other specified material at the interface with the named material Default none SILICON logical Print values in the other specified material at the interface with silicon Default false OXIDE logical Print values in the other specified material at the interface with oxide Default false OXYNITR logical Print values in the other specified material at the interface with oxynitride Default false NITRIDE logical Print values in the other specified material at the interface with nitride Default false POLYSIL logical Print values in the other
19. the COLOR parameter depend on the type of display being used Where possible the colors 2 through 7 have been set up to produce the col ors red green blue cyan light blue magenta light purple and yellow in that order Colors 8 and above produce a repeating series of 12 colors in rainbow order from red to violet IN FILE Parameter The format of the file specified by the IN FILE parameter can be either column wise or TIF In the case of a columnwise format the file may contain the follow ing two types of lines 1 Lines that are blank or contain a slash as the first nonblank character are ignored and can be used to document the file 2 Other lines define the data at one point in the distribution These lines must contain the following values a Value number X COLUMN is the horizontal coordinate of the point 3 134 Confidential and Proprietary S4 1999 2 TSUPREM 4 User s Manual PLOT 1D b Value number Y COLUMN is the vertical coordinate of the point If this line contains fewer than N numerical values in free field format where N is the maximum of indices X COLUMN and Y COLUMN for the values listed above the line is ignored Since the iv log file of Medici is a TIF format file the results of device simula tion can be plotted if TIF X AXIS and Y AXIS are specified This capability makes it possible to easily compare the electrical calculations of TSUPREM 4 and Medici The transformation of
20. through polysilicon at the interface with the other specified material Default false PHOTORES logical Plot a cross section through photoresist at the interface with the other specified material Default false ALUMINUM logical Plot a cross section through aluminum at the interface with the other specified material Default false MATERIA character Plot a cross section through the other specified material at the interface with the named material Default none SILICON logical Plot a cross section through the other specified material at the interface with silicon Default false OXIDE logical Plot a cross section through the other specified material at the interface with oxide Default false OXYNITR logical Plot a cross section through the other specified material at the interface with oxynitride Default false NITRIDE logical Plot a cross section through the other specified material at the interface with nitride Default false POLYSIL logical Plot a cross section through the other specified material at the interface with polysilicon Default false S4 1999 2 Confidential and Proprietary 3 129 Section 3 4 Output TSUPREM 4 User s Manual Parameter Type Definition PHOTORE logical Plot a cross section through the other specified material at the interface with photoresist Default false ALUMINU logical Plot a cross section through the other specified material at the interface with aluminum Defa
21. units of H for each unit of O2 to form HO Thus the effective flow contains zero units of O or H or both If the effective gas contains nonzero amounts of both O and H O the oxi dation rate is based on the partial pressure of HO The amount of chlorine in the ambient can be specified either by the flow of HCl F HCL parameter or by the percentage of HCl HCL parameter but not both If Confidential and Proprietary 3 111 Section 3 3 Process Steps TSUPREM 4 User s Manual the specified ambient contains O or HO oxidation takes place at interfaces between silicon dioxide and silicon or polysilicon A native oxide with thickness given by the INITIAL parameter on the AMBIENT statement is deposited on any exposed silicon or polysilicon surfaces before the start of the diffusion step ANTIMONY ARSENIC BORON and PHOSPHOR and the combination of IMPU RITY and I CONC specify the concentration of impurities at the wafer surface for predeposition The total pressure for an oxidizing ambient is given by PRES SURE To ramp the pressure specify either the ramp rate P RATE or the pres sure at the end of the step P FINAL The parameters for oxidation are set by the AMBIENT statement Diffusivities and segregation parameters are set on the various impurity statements i e the IMPURITY ANTIMONY ARSENIC BORON and PHOSPHORUS statements The oxidation and point defect models and the numerical methods to be used are specifie
22. uses Young s modulus YOUNG M and Poisson s ratio POISS R specified for each material with the MATERIAL statement The COMPRESS model is recommended for general use on arbitrary structures It includes the concentration dependence of oxidation rate and models the oxidation of polysilicon The VISCOELA model simulates viscoelastic flow in two dimensions It uses sim ple three nodes per triangle elements for speed but simulates elastic deforma tion as well as viscous flow When used with stress dependent parameters i e STRESS D true it can produce very accurate results with reasonable simulation times It is slower than the COMPRESS model but 10 100 times faster than the VISCOUS model with stress dependence It uses the YOUNG M POISS R VISC 0 VISC E and VISC X parameters for mechanical properties of materi als plus the VC VR VD and VDLIM parameters for describing stress dependence The VISCOUS model simulates incompressible viscous flow of the oxide using more complicated seven nodes per triangle elements It calculates stresses and is the only model that models reflow The VISCOUS model is slower than the COMPRESS and VISCOELA models and may require large amounts of memory it may be impossible to simulate large structures with this model on some comput ers due to memory limitations It uses the viscosity parameters VISC 0 VISC E and VISC X specified for each material with the MATERIAL state ment The VI
23. 4 AMB 5 F 0O2 lt n gt F H20 lt n gt F H2 lt n gt F N2 lt n gt F HCL lt n gt IMPURITY lt c gt I CONC lt n gt ANTIMONY lt n gt ARSENIC lt n gt BORON lt n gt PHOSPHOR lt n gt PRESSURE lt n gt P RATE lt n gt P FINAL lt n gt HCL lt n gt D RECOMB lt n gt MOVIE lt c gt DUMP lt n gt Parameter Type Definition TIME CONTINUE TEMPERAT T RATE T FINAL DRYO2 WETO2 3 108 number The duration of the diffusion step Units minutes Default none logical Indicates that this step is a continuation of a previous diffusion step No native oxide deposition occurs and the time step is not reset No processing steps should be specified between the preceding DIFFUSION statement and the DIFFUSION CONTINUE statement The starting temperature of the step should be the same as the final temperature of the preceding step and the ambi ent must also be the same Default false number The ambient temperature at the beginning of the step Units degrees Celsius Default none number The time rate of change of the ambient temperature Units degrees Celsius minute Default 0 0 number The ambient temperature at the end of the step Units degrees Celsius Default TEMPERAT logical Specifies that the ambient gas is dry oxygen Default false logical Specifies that the ambient gas is wet oxygen Default false Confidential and Proprietary S4 1999 2 TSUPREM
24. 5 Y 9 0 CM LABEL Oxide C RECT 2 The label ends at a point 12 5 cm from the x axis and 9 0 cm from the y axis It is preceded by a rectangle filled with color 2 3 The following statement stores the coordinate of the position at which a mouse is clicked LABEL LABEL x X CLICK px Y CLICK py The variables px py store the coordinate of the position at which a mouse is clicked Note The unit of the stored value in X CLICK is the same as the x coordinate unit However in the case of Y CLICK the unit is cm for the distance In PLOT 2D graph for example the variable of Y CLICK stores the y coordinate value in cm unit while the variable of X CLICK value stores the x coordinate value in um unit Confidential and Proprietary S4 1999 2 Section 3 5 Models and Coefficients TSUPREM 4 User s Manual AMBIENT The AMBIENT statement is used to specify oxidation coefficients OXIDE is a valid synonym for the AMBIENT statement AMBIENT DRYO2 WETO2 STEAM INERT AMB 1 AMB 2 AMB 3 AMB 4 AMB 5 F O2 lt n gt F H20 lt n gt F H2 lt n gt F N2 lt n gt F HCL lt n gt PRESSURE lt n gt HCL lt n gt 02 H20 lt 111 gt lt 110 gt lt 100 gt ORIENTAT lt n gt POLYSILI THINOX O lt n gt THINOX E lt n gt THINOX L lt n gt L LIN 0 lt n gt L LIN E lt n gt H LIN 0O lt n gt H LIN E lt n gt L PAR 0 lt n gt L PAR E lt n gt H PAR 0O lt n gt
25. DRY parameter is specified the etch region includes all material within a vertical distance THICKNES of the exposed surface This model the DRY model in previous versions of TSUPREM 4 has been replaced by the TRAPEZOI model The OLD DRY model in version 5 1 of TSUPREM 4 is the same as the DRY model in older versions of the program In version 5 1 DRY is a synonym for TRAPEZOI The TRAPEZOI model with default values of ANGLE and UNDERCUT is equivalent to the OLD DRY model except that surface layers of nonetchable material blocks etching of underlying material even if the sur face layer is thinner than THICKNES Specifying DRY in version 5 1 is equiv alent to specifying DRY in previous versions in cases of practical interest 6 Ifthe ALL parameter is specified the etch region includes the entire structure e If no region specification is given TRAPEZOT is assumed e Ifa material is specified only that material is etched otherwise the entire region specified is subject to removal It is possible to cut the structure into two or more pieces with an ETCH statement In this case all pieces except the one with the largest area are removed A warning is issued for each piece removed Note The ETCH statement except when used with the TERRAIN parameter is not intended to simulate a physical etching process its purpose is to pro vide a means to generate the required structures for simulation of diffu sion and oxidation Note in
26. ICKNES of an exposed sur face Default false S4 1999 2 Confidential and Proprietary 3 93 Section 3 3 Process Steps Parameter Type x number Y number OLD DRY logical ALL logical TOPOGRAP character Description TSUPREM 4 User s Manual Definition The x coordinate used with the START CONTINUE or DONE parameter Units microns Default none The y coordinate used with the START CONTINUE or DONE parameter Units microns Default none The exposed surface is etched vertically by an amount given by the THICKNES parameter Default false The specified material is etched away entirely Default false The name of a file containing Taurus Topography input commands that define the etch to be performed Default none Synonyms TERRAIN This statement is used to remove a portion of the current structure The user defines a region to be removed and may optionally specify a material to be removed if no material is specified all materials are considered to be etchable Portions of the structure are removed provided that they are of an etchable mate rial lie within the defined etch region and are exposed to the ambient See Chap ter 2 Etching on page 2 101 for a more complete description The surface under the etched portions of the structure is marked as exposed The warning xxx Warning No material removed by ETCH statement is produced by an attempt to etch a material that is not exposed or by speci
27. MESH statement lt 111 gt logical Specifies that the crystalline orientation of the silicon substrate is lt 111 gt Default false lt 110 gt logical Specifies that the crystalline orientation of the silicon substrate is lt 110 gt Default false lt 100 gt logical Specifies that the crystalline orientation of the silicon substrate is lt 100 gt Default True if no other orientation is specified 3 58 Confidential and Proprietary S4 1999 2 TSUPREM 4 User s Manual Parameter ORIENTAT ROT SUB X ORIENT RATIO LINE DAT IMPURITY I CONC I RESIST MATERIAL ANTIMONY ARSENIC BORON S4 1999 2 Type number number number number logical character number number character number number number INITIALIZE Definition The crystalline orientation of the silicon substrate Only 100 110 and 111 are recognized Units none Default 100 Synonyms Y ORIENT The rotation of the substrate about the y axis The reference orientation ROT SUB 0 is defined such that the x axis points in a lt 110 gt direction Units degrees Default 0 0 The crystalline orientation of the x axis This must be a 3 digit integer value Units none Default 110 The maximum ratio of adjacent grid spacings to be used in generating a grid Units none Default 1 5 Synonyms INTERVAL Specifies that the location of each x and y grid line be listed on the standard output and in the outp
28. P specifies the dashed line type of the line segment Type 1 produces a solid line while types 2 through 10 produce various styles of dashed lines C LINE specifies the color of the line and LENGTH gives the length If either Confidential and Proprietary 3 151 Section 3 4 Output Color Examples 3 152 TSUPREM 4 User s Manual SYMBOL or C SYMBOL is specified a symbol is drawn If RECTANGL C RECTAN W RECTAN or H RECTAN is specified a filled rectangle is drawn The SIZE parameter specifies the character size to be used for the label and the default width and height for filled rectangles The COLOR parameter specifies the color to be used for the label and the default color for any line segment symbol or filled rectangle Color 1 contrasts with the background e g black on white or white on black On most color devices col ors 2 through 7 produce red green blue cyan light blue magenta light purple and yellow while colors 8 and above give a repeating sequence of 12 colors in rainbow order red through violet The COLOR parameter has no effect on mono chrome devices 1 The following statements put two labels on the plot starting at x 3 microns and y 1 4 and 1 6 microns with a short line of the specified type before each one LABEL X LABEL X 3 0 Y 1 4 LABEL Arsenic LINE 3 3 0 Y 1 6 LABEL Phosphorus LINE 4 2 The following statement plots a label preceded by a filled rectangle LABEL RIGHT X 12
29. SCOUS model is needed only when stress calculations are required when the stress dependent oxidation parameters are used or when SKIP SIL must be set false in order to simulate structures with floating silicon mesas Confidential and Proprietary S4 1999 2 TSUPREM 4 User s Manual TSUPREM 4 User s Manual AMBIENT Stress The parameter STRESS D determines whether the stress dependence of oxidant Dependen ce diffusivity surface reaction rate and oxide viscosity are included when oxidizing with the VISCOELA or VISCOUS models When STRESS D is true these stress dependencies are included when STRESS D is false they are not The magnitude of the various stress effects are specified by the VC VR VT VD and VDLIM parameters e VC is the activation volume for the dependence of oxide viscosity on shear stress VC can be specified for arbitrary materials using the MATERIAL state ment e VRand VT are the activation volumes for the dependence of the surface reac tion rate on normal and tangential stresses respectively e WD is the activation volume for the dependence on pressure of the diffusivity of the oxidizing species in the oxide e VDLIM is the maximum increase in oxidant diffusivity produced by VD The parameters VC VD VR VT and TEMPERAT are used to specify the activation volumes as functions of temperature A separate table is maintained for each oxi dizing species and for each material in the case of VC Table
30. Section 3 2 Device Structure Specification TSUPREM 4 User s Manual INITIALIZE The INITIALIZE statement sets up the initial structure for a simulation INITIALIZE IN FILE lt c gt SCALE lt n gt FLIP Y TIF WIDTH lt n gt DX lt n gt lt 111 gt lt 110 gt lt 100 gt ORIENTAT lt n gt ROT SUB lt n gt X ORIENT lt n gt RATIO lt n gt LINE DAT IMPURITY lt c gt I CONC lt n gt I RESIST lt n gt MATERIAL lt c gt ANTIMONY lt n gt ARSENIC lt n gt BORON lt n gt PHOSPHOR lt n gt CONCENTR RESISTIV Parameter Type Definition IN FILE character Name of a saved structure file If this parameter is omitted a rectangular grid is generated using previously specified LINE ELIMINATE REGION and BOUNDARY statements Default none Synonyms INFILE SCALE number The mesh read in from IN FILE is scaled by this factor Units none Default 1 0 FLIP Y logical Specifies that the input structure is to be reflected about y 0 Default false TIF logical Specifies that the input file is a TIF Technology Interchange Format file Default false WIDTH number The width of the initial structure Only used if no LINE X statements are specified Units microns Default the width of the MASK information if any or 1 0 DX number The grid spacing to use in the x direction Units microns Default the current value of DX MAX from the
31. The exponent of the pressure in the expression for the linear oxidation rate Units none Default current value for this oxidant Synonyms L PDEP The exponent of the pressure in the expression for the parabolic oxidation rate Units none Default current value for this oxidant Synonyms P PDEP The pre exponential constant in the expression for the impurity concentration dependence of the linear oxidation rate Units none Default current value for this oxidant The activation energy in the expression for the impurity concentration depen dence of the linear oxidation rate Units electron volts Default current value for this oxidant Specifies that the TABLE parameter defines chlorine percentages associated with the rows in the table of coefficients modifying the linear oxidation rate in the presence of chlorine Default false Specifies that the TABLE parameter defines chlorine percentages associated with the rows in the table of coefficients modifying the parabolic oxidation rate in the presence of chlorine Default false Specifies that the TABLE parameter defines entries in a column of the table of coefficients modifying the linear oxidation rate in the presence of chlorine The column number is specified with the COLUMN parameter and is associated with the temperature specified by the TEMPERAT parameter Default false Specifies that the TABLE parameter defines entries in a column of the table of coefficients mod
32. Triangle Plus Upper case X Diamond Up arrow Roofed upper case X Upper case Z 10 Upper case Y 11 Curved square 12 Asterisk 13 Hourglass 14 Bar 15 Star OMANDNHKWNR If LABEL is specified the symbol is placed to the left of the label with one char acter space between the symbol and the label text If LABEL is not specified the rectangle is centered at the point given by X and Y Units none Default 1 The color of the symbol if any Units none Default COLOR Specifies that a filled rectangle be plotted with the label If LABEL is specified the rectangle is placed to the left of the label with one character space between the rectangle and the label text If LABEL is not specified the rectangle is cen tered at the point given by X and Y Default false The color of the filled rectangle Units none Default COLOR The width of the filled rectangle Units cm Default SIZE The height of the filled rectangle Units cm Default SIZE Confidential and Proprietary S4 1999 2 TSUPREM 4 User s Manual Description LABEL The LABEL statement is used to add text symbols and or filled rectangles to a plot This statement is meaningless unless a PLOT 1D PLOT 2D or PLOT 3D statement has been previously specified Label Placement The rules for placing these annotations are as follows 1 Labels are always placed at the location specified by X and Y The label is left justified centered or rig
33. Y LABEL lt c gt X SHIFT lt n gt Y SHIFT lt n gt X SCALE lt n gt Y SCALE lt n gt Y LOG X LOG ELECTRIC BOUNDARY CLEAR AXES SYMBOL lt n gt CURVE LINE TYP lt n gt COLOR lt n gt LEFT lt n gt RIGHT lt n gt BOTTOM lt n gt TOP lt n gt X OFFSET lt n gt X LENGTH lt n gt X SIZE lt n gt Y OFFSET lt n gt Y LENGTH lt n gt Y SIZE lt n gt T SIZE lt n gt Parameter Type Definition X VALUE number A vertical cross section is to be plotted at this value of x Units microns Default 0 0 Y VALUE number A horizontal cross section is to be plotted at this value of y Units microns Default none MATERIAL character Plot a cross section through the named material at the interface with the other specified material Default none 3 128 Confidential and Proprietary S4 1999 2 TSUPREM 4 User s Manual PLOT 1D Parameter Type Definition SILICON logical Plot a cross section through silicon at the interface with the other specified material Default false OXIDE logical Plot a cross section through oxide at the interface with the other specified material Default false OXYNITRI logical Plot a cross section through oxynitride at the interface with the other specified material Default false NITRIDE logical Plot a cross section through nitride at the interface with the other specified material Default false POLYSILI logical Plot a cross section
34. age 3 215 Taurus Lithography Files S4 1999 2 The DEPICT parameter allows you to create files to be read by Avant TCAD s Taurus Lithography program Files produced by Taurus Lithography do not contain the complete mesh and solution information required by TSUPREM 4 Rather they are used to update an existing structure with the results of a Taurus Lithography simulation Thus the usual sequence for interfacing with Taurus Lithography is 1 Generate a structure in TSUPREM 4 either from an initial mesh definition or by reading a saved structure 2 Save the structure in both TSUPREM 4 and Taurus Lithography formats This requires two SAVEFILE statements and two output files 3 Use Taurus Lithography to process the structure starting with the saved Taurus Lithography format file Save the results in a new Taurus Lithogra phy format file 4 Read the saved TSUPREM 4 format file into TSUPREM 4 with an INITIALIZE or LOADFILE statement 5 Read the new Taurus Lithography format file into TSUPREM 4 with a LOADFILE statement Confidential and Proprietary 3 69 Section 3 3 Process Steps TSUPREM 4 User s Manual DEPOSITION Parameter MATERIAL SILICON OXIDE OXYNITRI NITRIDE POLYSILI ALUMINUM PHOTORES POSITIVE NEGATIVE 3 84 The DEPOSITION statement is used to deposit a specified material on the exposed surface of the current structure DEPOSITION Type MATERIAL lt c gt SILICON
35. aining photoresist of the other type a warning is issued and the type of the old photore sist is changed to that of the newly deposited photoresist Deposition with Taurus Topography The TOPOGRAP parameter invokes Taurus Topography with the specified com mand input file The command input file contains Taurus Topography com mands describing one or more processing steps to be simulated by Taurus Topography It should not contain the INITIALIZE or STOP statements The values of variables set with the ASSIGN DEFINE and EXTRACT statements are substituted in the Taurus Topography command input file In addition to variables set explicitly by you if the THICKNES parameter is set on the DEPOSITION statement then its value is assigned to the variable THICK prior to substitution If the variable THICK is assigned in this way it will be unset after the DEPOSITION statement even if it was set by you previously This allows parameter values such as deposition thickness to be passed to Taurus Topogra phy The most recent mask file specified in the TSUPREM 4 input file is passed to Taurus Topography for use in masked etch steps By default Taurus Topography is called by requesting that the command topography be executed by the operating system but if the environment vari able S4TERRAIN is set its value is used instead It may be necessary for you to define other environment variables e g TERR_LIB for Taurus Topography to run correct
36. al charge neutrality and complete ionization of impurities S4 1999 2 Confidential and Proprietary 3 121 Section 3 4 Output TSUPREM 4 User s Manual Mathematical Operations and Functions 3 122 The symbols P and are used for the mathematical operations of addition subtraction multiplication division and exponentiation respectively In addition the following functions are available active electrically active part of impurity concentration gb concentration of impurity in polycrystalline grain boundaries abs absolute value diffusivity diffusivity in cm sec of an impurity or point defect species erf error function erfc complementary error function exp exponential log natural logarithm of the absolute value logl0 base 10 logarithm of the absolute value slogl0 base 10 logarithm of the absolute value times the sign of the value sqrt square root sin cos tan trigonometric functions arguments in radians asin acos inverse trigonometric functions results in radians atan sinh asinh hyperbolic and inverse hyperbolic functions cosh acosh tanh atanh The log log10 and slog10 functions return the value 0 0 if their argument is zero the log log10 slog10 and sqrt functions take absolute value of their arguments The following constant is available Kb Boltzmann s constant eV C Note The active and net concentrations depend on the temperature
37. ambient If H is also present the O and H are assumed to react completely to form H30 The flows of O and H3 are reduced and the flow of H O is increased Units none Default 0 0 The flow of H O associated with the specified ambient If O and H are also present the O and H are assumed to react completely to form H20 The flows of O and H are reduced and the flow of H3O is increased Units none Default 0 0 The flow of H associated with the specified ambient If O is also present the O and H are assumed to react completely to form HO The flows of O and H ware reduced and the flow of H O is increased Units none Default 0 0 Confidential and Proprietary 3 197 Section 3 5 Models and Coefficients TSUPREM 4 User s Manual Parameter F N2 F HCL PRESSURE HCL 02 H20 lt 111 gt lt 110 gt lt 100 gt ORIENTAT POLYSILI THINOX 0 THINOX E 3 198 Type number number number number logical logical logical logical logical number logical number number Definition The flow of N2 or other inert gasses associated with the specified ambient Units none Default 0 0 The flow of chlorine associated with the specified ambient Units none Default 0 0 The default value of total gas pressure for the specified ambient Units atmospheres Default the current value for this ambient initially 1 0 The default percentage of chlorine present for th
38. d on the METHOD statement The default values for these parameters are normally set by the s4init file which is read each time TSUPREM 4 is executed See Chapter 2 for complete descriptions of the models used for diffusion and oxi dation and Appendix A for a list of default model coefficients Oxidation Limitations Reflow 3 112 Oxidation of polysilicon is simulated only when the COMPRESS VISCOELA or VISCOUS model has been specified with the METHOD state ment The oxidation algorithms provide limited support for the case where silicon or polysilicon oxide and a third material meet at a point The results are reasonably accurate when only one of the materials in contact with oxide is oxidizing results are less accurate if both materials in contact with oxide are oxidizing at a signifi cant rate Impurities present in the ambient during an oxidation step are incorporated into the growing oxide Note however that the program does not currently contain models for the changes in physical properties of heavily doped glasses Reflow of surface layers occur whenever oxidation with the VISCOUS model is specified The amount of reflow is proportional to the ratio of the surface tension specified by the SURF TEN parameter on the MATERIAL statement to the vis cosity for each material Reflow can occur in any material having a nonzero value of SURF TEN Only exposed layers flow due to surface tension but underlying layers can de
39. degrees Kelvin and en the nitride thickness in microns Units microns Default the current value initially 8 25e 3 1580 3 Tox Fox e0x gt exp en 0 08 7 0 06 The ratio of the nitride lifting to the field oxide thickness for the ERFG Guillemot model This is an arithmetic expression involving the variables Fox the field oxide thickness in microns eox the pad oxide thickness in microns Tox the oxidation temperature in degrees Kelvin and en the nitride thickness in microns Units none Default the current value initially 402 0 445 1 75 en exp Tox 200 The nitride thickness en used in the equations for ERF LBB and ERF H Units microns Default none The temperature associated with the column in the chlorine tables given by the COLUMN parameter or a list of temperatures corresponding to the values of the VC VD VR and or VT parameters Units degrees Celsius Default none Clear table s specified by the VC VD VR and or VT parameters before adding new values see text Default none Confidential and Proprietary S4 1999 2 TSUPREM 4 User s Manual Parameter Type CM SEC logical Description AMBIENT Definition If true parameters involving time are specified in centimeters and seconds if false parameters involving time are in microns and minutes Default false All parameters relating to oxidation are specified on this statement The necessary parameters ar
40. e AMBIENT statement Additional AMBIENT Notes 1 3 210 Oxidant in materials other than oxide is allowed to diffuse and segregate but its concentration is then ignored no oxynitridation for instance The diffu sion coefficients in oxide and transport coefficients between oxide and silicon are derived from the Deal Grove coefficients so these parameters are ignored if read from input statements The analytic models use the thickness of the oxide to compute the growth rate and the ERFG model also uses the nitride thickness These values are not inferred from the structure Instead the value of NIT THIC is used for the nitride thickness and the oxide thickness is calculated by adding the oxide grown in a given high temperature step to the specified INITIAL oxide thickness Thus if the structure has other than INITIAL microns of oxide on it at the start of a diffusion step the thickness must be specified with the INITIAL parameter If there is no oxide on an exposed silicon surface a layer of oxide of thickness INITIAL is deposited If the INITIAL parame ter doesn t correspond to the actual oxide thickness the growth rate is incor rect The INITIAL parameter need not be set when an oxidation is continued with the CONTINUE parameter on the DIFFUSION statement The analytic models do not recognize masking layers in the structure The location of the presumed mask edge must be specified by the MASK EDG parameter The materia
41. e can also be read by older versions of TMA PISCES 2B and by other versions of PISCES Default false Synonyms PISCES Specifies that polysilicon regions should be converted to electrodes in the Medici output file Default false Specifies that an electrode should be placed along the backside of the structure in the Medici output file Default false Specifies that the saved output file contains a two dimensional doping profile that can be read by MINIMOS 5 Default false The x coordinate of the mask edge in the source area of the MINIMOS 5 simu lation region MINIMOS 5 interprets this coordinate as the left edge of the gate electrode Units microns Default none Specifies that the MINIMOS 5 simulation region includes only the source area of the device Either FULL DEV or HALF DEV must be specified if MINIMOSS is specified Default false Specifies that the MINIMOS 5 simulation region includes both the source and drain areas of the device Either FULL DEV or HALF DEV must be specified if MINIMOSS is specified Default false The x coordinate of the mask edge in the drain area of the MINIMOS 5 simula tion region MINIMOS 5 interprets this coordinate as the right edge of the gate electrode X MASK D must be specified if FULL DEV is specified it must not be specified if HALF DEV is specified Units microns Default none The x coordinate of the center of the channel of the MINIMOS 5 simulation region
42. e following statements print the x and y coordinates of the interface between silicon and oxide SELECT Z y PRINT 1D SILICON OXIDE 3 The following statements prints junction depths SELECT Z doping PRINT LAYERS X V 0 3 126 Confidential and Proprietary S4 1999 2 TSUPREM 4 User s Manual S4 1999 2 PRINT 1D The PRINT statement assumes that a new layer begins whenever the selected value net doping in this case changes sign The following statements print the thicknesses of material layers SELECT Z 1 0 PRINT LAYERS X V 0 The SELECT statement specifies a constant value of one so the PRINT state ment only uses material boundaries to define layers Further when the value 1 0 is integrated over each layer the result is just the layer thickness Confidential and Proprietary 3 127 Section 3 4 Output TSUPREM 4 User s Manual PLOT 1D The PLOT 1D statement plots the value of the selected expression along a line through the structure PLOT 1D X VALUE lt n gt Y VALUE lt n gt MATERIAL lt c gt SILICON OXIDE OXYNITRI NITRIDE POLYSILI PHOTORES ALUMINUM MATERIA lt c gt SILICON OXIDE OXYNITR NITRIDE POLYSIL PHOTORE ALUMINU AMBIENT REFLECT I IN FILE lt c gt TIF X AXIS lt c gt Y AXIS lt c gt COLUMN X COLUMN lt n gt Y COLUMN lt n gt ROW X ROW lt n gt Y ROW lt n gt X LABEL lt c gt
43. e set by AMBIENT statements in the s4init file but can be changed by the user Oxidation Models ERFC Model S4 1999 2 The following models are available 1 Anerror function fit to bird s beak shapes the ERFC model 2 A parameterized error function model from the literature the Guillemot or ERFG model 3 A model in which oxidant diffuses and the oxide grows vertically at a rate determined by the local oxidant concentration the VERTICAL model 4 A compressible viscous flow model the COMPRESS model 5 A viscoelastic flow model the VISCOELA model 6 Anincompressible viscous flow model the VISCOUS model A summary of the features and characteristics of these models follows full descriptions are given in Chapter 2 Oxidation on page 2 44 Note Oxidation of polycrystalline silicon is modeled by the COMPRESS VISCOELA and VISCOUS models only The ERFC model is the fastest of the oxidation models It can be used for uniform oxidation of bare silicon provided that modeling of the concentration dependence of the oxidation rate is not needed It can be used for nonuniform oxidation of pla nar surfaces provided that fitting data for the lateral spread of the bird s beak is available The ERFC model is controlled by the SPREAD MASK EDG and INITIAL parameters The growth rate vs time is computed assuming an initial oxide thick ness INITIAL at the start of each diffusion step This model should not be used
44. e specified ambient Units percent Default calculated from F HCL Specifies that the oxidation coefficients are associated with the O oxidizing species Default false Specifies that the oxidation coefficients are associated with the H2O oxidizing species Default false Specifies that linear and thin oxide growth rate coefficients apply to lt 111 gt orientation silicon Default false Specifies that linear and thin oxide growth rate coefficients apply to lt 110 gt orientation silicon Default false Specifies that linear and thin oxide growth rate coefficients apply to lt 100 gt orientation silicon Default false Specifies that linear and thin oxide growth rate coefficients apply to silicon of the specified orientation Allowed values are 111 110 and 100 Units none Default 100 The specified coefficients apply to polysilicon or the interface between polysili con and some other material Default false The pre exponential constant in the expression for the thin oxide growth rate parameter Units microns min or cm sec Default current value for this orientation and oxidant The activation energy in the expression for the thin oxide growth rate parameter Units electron volts Default current value for this orientation and oxidant Confidential and Proprietary S4 1999 2 TSUPREM 4 User s Manual Parameter THINOX L L LIN 0 L LIN E H LIN O H LIN E S4 1999 2 Type number number
45. en the specified material and oxynitride Default false The specified coefficients apply to the interface between the specified material and nitride Default false The specified coefficients apply to the interface between the specified material and polysilicon Default false The specified coefficients apply to the interface between the specified material and gas Default false Synonyms GAS The pre exponential constant in the expression for segregation of oxidant between the two specified materials Units none Default current value for this oxidant and these materials Confidential and Proprietary S4 1999 2 TSUPREM 4 User s Manual Parameter Type SEG E number TRANS 0 number TRANS E number ALPHA number STRESS D logical VR character VT character VD character VDLIM number S4 1999 2 AMBIENT Definition The activation energy in the expression for segregation of oxidant between the two specified materials Units electron volts Default current value for this oxidant and these materials The pre exponential constant in the expression for transport of oxidant between the two specified materials Units microns min or cm sec Default the current value for this oxidant and these materials Synonyms TRN 0 The activation energy in the expression for transport of oxidant between the two specified materials Units electron volts Default the current value for this oxidant and these materia
46. entration atoms cm boron boron concentration atoms cm phosphorus phosphorus concentration atoms cm Confidential and Proprietary S4 1999 2 TSUPREM 4 User s Manual doping oxygen silicon interstitial vacancy damage ci star cv star trap cl_interst dloop rloop grain electron xv yy Sxx Sxy Syy x y net active concentration atoms cm oxidant concentration atoms cm silicon concentration in silicide atoms cm interstitial concentration cm gt vacancy concentration cm damage concentration cm equilibrium interstitial concentration cm equilibrium vacancy concentration cm concentration of filled interstitial traps cm concentration of clustered interstitials cm density of dislocation loops cm gt radius of dislocation loops cm average polycrystalline grain size um concentration of electrons em x velocity cm sec y velocity cm sec components of the stress tensor dynes cm x coordinate microns y coordinate microns e The names of user specified impurities can also be used giving the concentra tion of the impurity in atoms cm e The chemical concentration is reported unless the active function is used for example active phosphorus e The net concentration is defined as the sum of the donor concentrations minus the sum of the acceptor concentrations e The electron concentration is calculated using the assumptions of loc
47. f the plot variable Units units of the selected expression Default maximum value of the selected expression Synonyms Y MAX The distance by which the left end of the horizontal axis is offset from the left edge of the graphics viewport Units cm Default 2 0 The length of the horizontal axis Units cm Default viewport width X OFFSET 1 25 The height of the characters used to label the horizontal axis Units cm Default 0 25 The distance by which the bottom end of the vertical axis is offset from the bot tom edge of the graphics viewport Units cm Default 2 0 The length of the vertical axis Units cm Default viewport height Y OFFSET 1 25 The height of the characters used to label the vertical axis Units cm Default 0 25 The height of the characters in the character string used as the plot title Units cm Default 0 4 The PLOT 1D statement plots cross sections vertically or horizontally through the device or along an interface between two materials or along a boundary of the device The statement has options to provide for initialization of the graphics Confidential and Proprietary 3 133 Section 3 4 Output TSUPREM 4 User s Manual device and plotting of axes The statement can optionally draw vertical lines whenever a material boundary is crossed The vertical axis corresponds to the variable selected with the SELECT statement Limits can be specified so that only a portion of the enti
48. form due to stresses produced by reflow of the exposed layers Reflow in an inert ambient can be approximated by specifying an oxidizing ambi ent with a negligible partial pressure of oxidant e g by setting PRESSURE 1e 6 or by a combination such as F N2 1 0 and F 02 1e 6 Note that a native oxide Confidential and Proprietary S4 1999 2 TSUPREM 4 User s Manual Examples S4 1999 2 DIFFUSION is added whenever the partial pressure of the oxidizing species is nonzero it may be necessary to do a shallow etch to remove this oxide following a reflow step 1 The following statement specifies a 1000 degree 30 minute boron predeposi tion DIFFUSION TIME 30 TEMP 1000 BORON 1E20 2 The following statement calls for a 30 minute diffusion in an inert ambient DIFFUSION TIME 30 TEMP 800 T FINAL 1000 INERT The temperature is ramped from 800 C to 1000 C during the step 3 The following statement calls for a 60 minute dry oxidation at 900 C with an ambient containing 2 percent HCl DIFFUSION TIME 60 TEMP 900 DRYO2 HCL 2 4 The following statement performs a 30 minute 1000 C diffusion DIFFUSION TIME 30 TEMP 1000 MOVIE SELECT Z 10g10 Boron PLOT 1D X V 1 0 The boron concentration is plotted before each time step Confidential and Proprietary 3 113 Section 3 4 Output SELECT Parameter Type Z character TEMPERAT number LABEL character TITLE character Description Solution Values 3 120 TSUPREM 4 U
49. fying etch coordinates that do not include any etchable material Removing Regions 3 94 You can specify the region to be removed in one of the following ways 1 If TRAPEZOT is specified the etch region is found from a simple model of a primarily anisotropic i e vertical or directional etch with a small isotropic component This model can produce profiles with sloped sidewalls and under cutting of masking layers See Chapter 2 The Trapezoidal Etch Model on page 2 103 2 If LEFT or RIGHT is specified the etch region includes all material to the left or right of the line between P1 X P1 Y and P2 X P2 Y 3 The START CONTINUE and DONE parameters are used with the X and Y parameters to define arbitrarily complex etch regions The boundary of the region is determined by a series of ETCH statements each specifying a point on the boundary The first statement of the series should contain the START Confidential and Proprietary S4 1999 2 TSUPREM 4 User s Manual parameter the last should contain the DONE parameter and statements in between should use the CONTINUE parameter The last point is connected to the first point to produce a closed region defining the portion of the structure to be removed 4 If ISOTROPT is specified the etch region includes all material within the dis tance THICKNES of the exposed surface This produces a simple isotropic etch without rounding of outside corners 5 Ifthe OLD
50. g species are associated with the wet oxygen ambient Default false Specifies that the pressure chlorine percentage and flows of oxidizing and non oxidizing species are associated with the steam ambient Default false Specifies that the pressure chlorine percentage and flows of oxidizing and non oxidizing species are associated with the inert ambient Default false Synonyms NEUTRAL NITROGEN Specifies that the pressure chlorine percentage and flows of oxidizing and non oxidizing species are associated with ambient number one Ambient number one is defined by the user Default false Specifies that the pressure chlorine percentage and flows of oxidizing and non oxidizing species are associated with ambient number two Ambient number two is defined by the user Default false Specifies that the pressure chlorine percentage and flows of oxidizing and non oxidizing species are associated with ambient number three Ambient number three is defined by the user Default false Specifies that the pressure chlorine percentage and flows of oxidizing and non oxidizing species are associated with ambient number four Ambient number four is defined by the user Default false Specifies that the pressure chlorine percentage and flows of oxidizing and non oxidizing species are associated with ambient number five Ambient number five is defined by the user Default false The flow of O associated with the specified
51. ge 1 to 15 Values of this parameter are associated with the following symbols Square Circle Triangle Plus Upper case X Diamond Up arrow Roofed upper case X Upper case Z 10 Upper case Y 11 Curved square 12 Asterisk 13 Hourglass 14 Bar 15 Star OMANDNHWN RK Units none Default no symbols drawn Specifies that a line is to be drawn through the data points Default true The dashed line type used for the plotted data The axes are always drawn with line type 1 Units none Default 1 The color of line used for the plotted data The axes are always drawn with color 1 Units none Default 1 The minimum value to be plotted on the x axis Units microns Default minimum x or y coordinate of the structure Synonyms X MIN Confidential and Proprietary S4 1999 2 TSUPREM 4 User s Manual Parameter Type RIGHT number BOTTOM number TOP number X OFFSET number X LENGTH number X SIZE number Y OFFSET number Y LENGTH number Y SIZE number T SIZE number Description S4 1999 2 PLOT 1D Definition The maximum value to be plotted on the x axis Units microns Default maximum x or y coordinate of the structure Synonyms X MAX The minimum value of the selected expression to be plotted in units of the plot variable Units units of the selected expression Default minimum value of the selected expression Synonyms Y MIN The maximum value of the selected expression to be plotted in units o
52. gt ANGLE lt n gt UNDERCUT lt n gt LEFT RIGHT P1 X lt n gt P1 Y lt n gt P2 X lt n gt P2 Y lt n gt START CONTINUE DONE X lt n gt Y lt n gt ISOTROPI OLD DRY THICKNES lt n gt ALL TOPOGRAP lt c gt Parameter Type Definition MATERIAL character The name of the material to be etched Default none SILICON logical Etch silicon only Default false OXIDE logical Etch oxide only Default false OXYNITRI logical Etch oxynitride only Default false NITRIDE logical Etch nitride only Default false POLYSILI logical Etch polysilicon only Default false PHOTORES logical Etch photoresist only Default false ALUMINUM logical Etch aluminum only Default false TRAPEZOI logical Use an etch model that removes material from a trapezoidal region when applied to a planar surface This is a generalization of the DRY model in older versions of TSUPREM 4 Default true Synonyms DRY 3 92 Confidential and Proprietary S4 1999 2 TSUPREM 4 User s Manual ETCH Parameter Type Definition THICKNES number The thickness of the layer to be removed when the TRAPEZOT or OLD DRY parameter is specified Units microns Default UNDERCUT tan ANGLE for ANGLE lt 90 infinite otherwise no default if OLD DRY is specified ANGLE number The angle of the sidewalls produced when the TRAPEZOT parameter is speci fied The angle is measured from the horizontal so that vertical
53. he following parameters are dependent on the oxidizing species O or H20 L LIN 0 L LIN E H LIN 0O H LIN E LIN BREA LIN PDEP L PAR 0 L PAR E H PAR 0 H PAR E PAR BREA PAR PDEP GAMMA 0 GAMMA E LIN PCT PAR PCT LIN CLDE PAR CLDE COLUMN TEMPERAT TABLE THINOX 0 THINOX E THINOX L D O D E VC HENRY CO SEG 0 SEG E TRANS 0 and TRANS E VD VR and VT also depend on the oxidizing species but apply to both O and H20 if neither is specified The following parameters are dependent only on the first material specified D 0 D E VC HENRY CO and THETA The following parameters are dependent on both materials specified SEG 0 SEG E TRANS 0 TRANS E and ALPHA Parameters whose units include time are specified in units of microns and min utes unless CM SEC is true in which case units of centimeters and seconds are assumed Confidential and Proprietary 3 209 Section 3 5 Models and Coefficients TSUPREM 4 User s Manual Examples The statement AMBIENT AMB 1 F 02 0 90 F N2 0 08 F HCL 0 02 PRESSURE 2 0 defines ambient AMB 1 to consist of 90 oxygen and 2 chlorine at a pressure of two atmospheres The statement AMBIENT H20 MAT NITRIDE vc 130 170 TEMP 900 1000 replaces any values for temperatures between 900 C and 1000 C in the table for VC of nitride in ambients containing H20 3 The initialization file s4init contains the definitive set of examples of use of th
54. hography stored its results in file STRFRDEP they could be read into TSUPREM 4 with the statements INITIALIZE IN FILE STRTS4 LOADFILE IN FILE STRFRDEP DEPICT The statements LOADFILE IN FILE savestr and INITIALIZE IN FILE savestr are equivalent except that the program recognizes that an initial structure has been set up in the second case An INITIALIZE statement must be given before any processing or output statement can be processed Confidential and Proprietary S4 1999 2 TSUPREM 4 User s Manual SAVEFILE Parameter Type OUT FILE character TEMPERAT number SCALE number FLIP Y logical TIF logical TIF VERS character S4 1999 2 SAVEFILE The SAVEFILE statement writes mesh and solution information to a file SAVEFILE OUT FILE lt c gt TEMPERAT lt n gt SCALE lt n gt FLIP Y ACTIVE TIF TIF VERS lt c gt DEPICT MEDICI POLY ELE ELEC BOT MINIMOS5 X MASK S lt n gt HALF DEV FULL DEV X MASK D lt n gt X CHANNE lt n gt ha X MIN lt n gt X MAX lt n gt Y MIN lt n gt Y MAX lt n gt DX MIN lt n gt DY MIN lt n gt WAVE ACTIVE CHEMICAL DEFECT OXID MISC Definition The identifier of the structure file to be written Default none Synonyms OUTFILE The temperature used for evaluating active impurity concentrations Units Celsius Default the last processing temperature specified or 800 C A scaling factor to be a
55. ht justified at this location depending on whether LEFT CENTER or RIGHT is specified 2 The placement of line segments depends on whether a LABEL is specified a Ifa LABEL is specified the line segment is placed one character width to the left of the label b Ifno LABEL is specified the line segment is centered at the location spec ified by X and Y 3 The placement of symbols and filled rectangles depends on whether a line segment or label is specified a Ifa line segment is specified the symbol or filled rectangle is centered on the line segment b Ifno line segment is specified but a LABEL is specified the symbol or filled rectangle is placed one character width to the left of the label c Ifneither a line segment nor a LABEL is specified the symbol or filled rectangle is centered at the location specified by X and Y 4 The coordinates X and Y should be in the units of the plot axes e g microns or 1 cm unless CM is specified Note Some graphics devices have a cursor whose position can be read by the program On such devices a LABEL statement without X and Y coordi nates attempts to read the cursor position and plot the label at that point On terminals from which the cursor position cannot be read a LABEL statement without X and Y coordinates may produce unpredictable results Line Symbol and Rectangle S4 1999 2 If LINE TYP C LINE or LENGTH is specified a line segment is drawn LINE TY
56. ies that the vertical axis for Y COLUMN data in the IN FILE file is logarithmic Default the current value dependent on Z quantity in the SELECT statement Synonyms LOG X LOG logical Specifies that the horizontal axis for X COLUMN data in the IN FILE file is logarithmic Default the current value in the previous specification Otherwise false ELECTRIC logical Specifies plotting of results from a preceding ELECTRICAL statement Default false BOUNDARY logical If true material boundaries that are crossed are indicated by dashed vertical lines on the plot Default true CLEAR logical If true the graphics screen is cleared before the graph is drawn Default true S4 1999 2 Confidential and Proprietary 3 131 Section 3 4 Output Parameter AXES SYMBOL CURVE LINE TYP COLOR LEFT 3 132 Type logical number logical number number number TSUPREM 4 User s Manual Definition Specifies that axes should be drawn using scaling information from this state ment and or the current structure If AXES is false no axes are drawn and scaling information from the previous plotting statement is used i e LEFT RIGHT BOTTOM and TOP are ignored If AXES is false and no previous plotting state ment has been given an error is reported Default true Synonyms AXIS The type of centered symbol to be drawn at each point where the cross section intersects a mesh line This value must be in the ran
57. iffusion in arbitrary layers but the diffusion coefficient in oxide is derived from the para bolic rate constant The transport coefficient between the ambient and oxide is interpreted as the gas phase mass transport coefficient for the specified oxidizing species The effects of chlorine in the ambient gas on the oxidation rate of silicon are spec ified by tables of coefficients that modify the linear and parabolic oxidation rates There are two tables for each oxidizing species one each for the linear and para bolic oxidation rates The tables are two dimensional with at most 8 rows corre sponding to chlorine percentages and at most 8 columns corresponding to ambient temperatures Linear interpolation is used to obtain values for temperatures or per centages between the values in the table For temperatures or percentages outside of the range of values present in the table the values in the first or last rows or col umns as appropriate are used For example consider the following table of chlorine coefficients with six rows of chlorine percentages and five columns of temperatures 1 2 3 4 5 column row 800 900 1000 1100 1200 temperature 1 0 1 0 1 0 1 2 0 TO 1 0 2 1 liga 1 2 ees 1 4 Teed 3 3 126 Tf TS 1 9 2 0 4 5 24I 2 2 Zi 3 2 4 245 5 7 20 257 2 8 2 9 SSO 6 10 Zel 3 2 33 3 3 4 3 55 If this table represented the modification coefficients for the linear oxidation rates for the O2 oxidizing species it could have been defined w
58. ify the initial impurity concentrations or resistivity in the deposited layer depending on whether CONCENTR or RESISTIV is true Doping can also be specified with the IMPURITY and I CONC or I RESIST parameters The deposited material conforms to the contours of the original surface Outside corners on the original surface produce arcs on the new surface which are approx imated by straight line segments The maximum segment length is set by the ARC SPAC parameter The SPACES DY and YDY parameters used to control the grid spacing in the deposited layer are scaled by the value of the GRID FAC parameter on the MESH statement see Chapter 2 Changes to the Mesh During Processing on page 2 7 Note It is not possible to deposit a layer on the bottom of a structure even if it is exposed Attempting to do so may cause the program to fail Confidential and Proprietary S4 1999 2 TSUPREM 4 User s Manual J EPOSITION Polycrystalline Materials The TEMPERAT and GSZ LIN parameters are used only when depositing a poly crystalline material If no temperature is specified or if the temperature is less than the value of TEMP BRE for the material the deposited layer is amorphous recrystallization occurs at the start of the next high temperature step Photoresist Photoresist can be positive or negative but all photoresist in a structure must be of the same type If photoresist of one type is deposited on a structure cont
59. ifying the parabolic oxidation rate in the presence of chlorine The column number is specified with the COLUMN parameter and is associated with the temperature specified by the TEMPERAT parameter Default false Confidential and Proprietary S4 1999 2 TSUPREM 4 User s Manual Parameter COLUMN TABLE MATERIAL SILICON OXIDE OXYNITRI NITRIDE POLYSILI AMBIENT S4 1999 2 Type number character character logical logical logical logical logical logical number AMBIENT Definition The column number in the tables of coefficients modifying the linear or para bolic oxidation rates The coefficients defined by the TABLE parameter are stored in this column of a table The column number is associated with the tem perature specified by the TEMPERAT parameter There can be at most 8 columns in a table and each column corresponds to one temperature Units none Default none This parameter is interpreted as a series of numeric values separated by spaces or commas If the LIN PCT or PAR PCT parameter is specified the TABLE parameter defines the chlorine percentages associated with the rows in the table of coefficients modifying the linear or parabolic oxidation rates respectively If the LIN CLDE or PAR CLDE parameter is specified the TABLE parameter defines the entries in a column of the table of coefficients modifying the linear or parabolic oxidation rates respectively There can be
60. increased Units none Default 0 0 F H2 number The flow of H2 associated with the ambient gas If O2 is also present the O2 and H2 are assumed to react completely to form H2O The flows of O2 and H2 are reduced and the flow of H20 is increased Units none Default 0 0 F N2 number The flow of N2 and other inert components associated with the ambient gas Units none Default 0 0 F HCL number The flow of chlorine associated with the ambient gas Units none Default 0 0 S4 1999 2 Confidential and Proprietary 3 109 Section 3 3 Process Steps TSUPREM 4 User s Manual Parameter Type Definition IMPURITY character The name of an impurity present in the ambient gas at the surface of the structure Default none I CONC number The concentration of IMPURITY in the ambient gas at the surface of the wafer Units atoms cm Default none ANTIMONY number The concentration of antimony in the ambient gas at the surface of the structure Units atoms cm Default 0 0 Synonyms SB ARSENIC number The concentration of arsenic in the ambient gas at the surface of the structure Units atoms cm Default 0 0 Synonyms AS BORON number The concentration of boron in the ambient gas at the surface of the structure Units atoms cm Default 0 0 Synonyms B PHOSPHOR number The concentration of phosphorus in the ambient gas at the surface of 116 the structure Units atoms cm Default 0 0 Synonyms P PRESSURE number The total pres
61. ith the following series of input statements AMBIENT O2 LIN PCT TABLE 0 1 3 5 7 10 AMBIENT O2 LIN CLDE COLUMN 1 TEMPERAT 800 TABLE 1 0 1 1 1 6 2 1 2 6 3 1 AMBIENT 02 LIN CLDE COLUMN 2 TEMPERAT 900 TABLE 1 0 1 2 1 7 2 2 2 7 3 2 AMBIENT O2 LIN CLDE COLUMN 3 TEMPERAT 1000 TABLE 1 0 1 3 1 8 2 3 2 8 3 3 AMBIENT O2 LIN CLDE COLUMN 4 TEMPERAT 1100 TABLE 1 0 1 4 1 9 2 4 2 9 3 4 AMBIENT O2 LIN CLDE COLUMN 5 TEMPERAT 1200 TABLE 1 0 1 5 2 0 2 5 3 0 3 5 Confidential and Proprietary S4 1999 2 TSUPREM 4 User s Manual AMBIENT The following values are obtained from this table for the indicated percentages and temperatures percent temperatur table value row column Tao 1000 133 2 3 1 0 1050 1 35 2 3 4 2 0 1000 LSS Zi 3 T270 1000 ee 6 3 13 0 700 Ped 2 1 T 1250 T5 2 5 2 0 1250 TSTS PATAS 5 Parameter Dependencies Orientation Oxidizing Species Specified Material Specified Units S4 1999 2 Parameters which have special dependencies are listed below If insufficient infor mation is given with a parameter e g L LIN 0 without an orientation and an oxidant the parameter is ignored without warning The following parameters are dependent on the specified orientation L LIN 0 L LIN E H LIN 0 H LIN E THINOX 0 THINOX E and THINOX L Note that POLYSILI can be used in place of the orientation to specify coeffi cients for oxidation of polysilicon T
62. ity with which the deposited layer is doped Default none I CONC number The concentration of the specified IMPURITY in the deposited layer Units atoms cm Default none I RESIST number The resistivity of the deposited layer Units ohm cm Default none ANTIMONY number The uniform concentration or resistivity of antimony in the deposited layer Units atoms cm or ohm cm Default 0 0 Synonyms SB ARSENIC number The uniform concentration or resistivity of arsenic in the deposited layer Units atoms cm or ohm cm Default 0 0 Synonyms AS BORON number The uniform concentration or resistivity of boron in the deposited layer Units atoms cm or ohm cm Default 0 0 Synonyms B PHOSPHOR number The uniform concentration or resistivity of phosphorus in the deposited layer Units atoms cm or ohm cm Default 0 0 Synonyms P CONCENTR logical Specifies that the impurity concentration in the deposited layer is given Default true RESISTIV logical Specifies that the resistivity in the deposited layer is given Default false THICKNES number The thickness of the deposited layer Units microns Default none SPACES number The number of vertical grid spacings in the layer This value is divided by the value of GRID FAC see MESH on page 3 44 Units none Default 1 GRID FAC Synonyms DIVISION DY number The nominal grid spacing to be used in the deposited material layer at the loca tion specified by the YDY para
63. l viscosities have been calibrated for the VISCOELA model with stress dependence enabled For use without stress dependence with either the VISCOELA or VISCOUS model it may be necessary to modify the viscosity values Confidential and Proprietary S4 1999 2
64. ls Synonyms TRN E The volume expansion ratio between the two specified materials The defaults are 0 44 for silicon oxide and polysilicon oxide and 1 0 for all other combina tions Units none Default the current value for these materials Specifies that the stress dependent models for oxide viscosity oxidant diffusiv ity and surface reaction rate are to be used Default the current value A table of activation volumes as a function of temperature for the dependence of oxidation rate at the Si SiO interface on normal stress for the specified oxidiz ing species O2 or H20 Entries in the table correspond to temperatures given by the TEMPERAT parameter see text Units A Default the current value initially 15 A table of activation volumes as a function of temperature for the dependence of oxidation rate at the Si SiO interface on tangential stress for the specified oxi dizing species O2 or H20 Entries in the table correspond to temperatures given by the TEMPERAT parameter see text Units A Default the current value initially 0 0 A table of activation volumes as a function of temperature for the dependence of oxidant diffusivity in oxide on pressure for the specified oxidizing species O2 or H20 Entries in the table correspond to temperatures given by the TEMPERAT parameter see text Units A Default the current value initially 75 The maximum increase in oxidant diffusivity produced by the VD para
65. ly For additional details refer to the Taurus Topography Reference Manual When Taurus Topography is invoked with the DEPOSITION statement the full set of parameters is used for any deposited layer of the specified material Thus you have full control over grid spacing doping and polycrystalline grain size Note that the parameters specified on the DEPOSITION statement only apply to the specified material They are ignored for other materials deposited by Taurus Topography S4 1999 2 Confidential and Proprietary 3 87 Section 3 3 Process Steps Examples TSUPREM 4 User s Manual The following statement deposits 200 angstroms of silicon dioxide DEPOSIT OXIDE THICK 0 02 The following statement deposits a one micron thick layer of photoresist using four grid spaces in the layer DEPOSIT PHOTO THICK 1 0 SPACES 4 ARC SPAC 0 1 The maximum segment length used to approximate arcs is 0 1 micron By default the newly deposited photoresist and any photoresist already present in the structure is assumed to be positive The following statement deposits 0 1 micron of poly DEPOSIT MAT POLY THICK 0 1 TEMPERAT 650 GSZ LIN The initial grain size is calculated at 650 C and increases linearly over the thickness of the layer with minimum value at the bottom of the layer The following statement calls Taurus Topography with the input command file PolyDep inp DEPOSIT MAT POLY THICK 0 1 TEMPERAT 650 GSZ LIN TOPOGRAPHY PolyDep i
66. meter Units none Default the current value initially 1 2 Confidential and Proprietary 3 203 Section 3 5 Models and Coefficients TSUPREM 4 User s Manual Parameter INITIAL SPREAD MASK EDG ERF Q ERF DELT ERF LBB ERF H NIT THIC TEMPERAT CLEAR 3 204 Type number number number number number character character number character logical Definition The thickness of the existing oxide at the start of oxidation Exposed silicon sur faces are covered with this thickness of native oxide before oxidation begins Units microns Default the current value initially 0 002 The ratio of width to height for the bird s beak used in the ERF C model of local oxide shape Units none Default the current value initially 1 0 The assumed position of the mask used by the analytical models for local oxida tion Oxide grows to the right of the mask edge Units microns Default the current value initially 200 The q parameter for the ERFG Guillemot model Units microns Default the current value initially 0 05 The delta parameter for the ERFG Guillemot model Units microns Default the current value initially 0 04 The length of the bird s beak for the ERFG Guillemot model This is an arith metic expression involving the variables Fox the field oxide thickness in microns eox the pad oxide thickness in microns Tox the oxidation tempera ture in
67. meter This value is multiplied by the value of GRID FAC see MESH on page 3 44 Units microns Default GRID FAC THICKNES SPACES Synonyms DX S4 1999 2 Confidential and Proprietary 3 85 Section 3 3 Process Steps Parameter Type YDY number ARC SPAC number TEMPERAT number GSZ LIN logical TOPOGRAP character Description 3 86 TSUPREM 4 User s Manual Definition The location of the nominal grid spacing specified by DY relative to the top of the deposited layer Units microns Default 0 0 Synonyms XDX The maximum spacing allowed along an arc on the new surface This value is multiplied by the value of GRID FAC see MESH on page 3 44 Units microns Default 0 5 THICKNES GRID FAC The deposition temperature used to determine initial grain size when deposit ing polycrystalline materials Units degrees Default 0 0 Kelvins Specifies that the grain size increases linearly with depth from the bottom of the deposited layer If false grain size is constant through the layer Default true The name of a file containing Taurus Topography input commands that define the deposition to be performed Default none Synonyms TERRAIN This statement provides a basic deposition capability Material is deposited on the exposed surface of the structure with the upper surface of the deposited layer becoming the new exposed surface The ANTIMONY ARSENIC BORON and PHOSPHOR parameters spec
68. model are automatically set through information stored in the file You need not respecify these parameters after reading in a structure file at the start of a simulation Crystalline Orientation 3 60 The crystalline orientation of any silicon regions in a generated structure can be specified by lt 100 gt lt 110 gt or lt 111 gt parameters The ORIENTAT parameter is also accepted for compatibility with older versions of the program The specified Confidential and Proprietary S4 1999 2 TSUPREM 4 User s Manual INITIALIZE orientation is used for all single crystal silicon regions in the simulation whether present in the initial structure or deposited later By default the x axis points in a lt 110 gt direction This can be changed by specifying a rotation about the y axis ROT SUB or the crystal orientation of the x axis X ORIENT The orientation parameters do not apply when reading a structure from a file the orientation of the saved structure is used instead Specifying Initial Doping Examples S4 1999 2 The ANTIMONY ARSENIC BORON and PHOSPHOR parameters can be used to specify the initial resistivity or impurity concentrations in the structure Any com bination of these parameters can be specified if impurity concentrations are given CONCENTR true but only one impurity can be specified if the resistivity is given RESISTIV true An impurity can also be specified by name with the IMPURITY paramete
69. np References to THICK in the Taurus Topography input file are replaced with the value 0 1 If the call to Taurus Topography causes the deposition of a polysilicon layer then the specified temperature and grain size model are used for that layer Additional DEPOSITION Notes 1 3 88 The calculation of doping concentration from resistivity uses mobility tables for silicon and polysilicon If the resistivity is specified when depositing some other material a warning is issued The mobility tables used for calculating the doping concentration are not the same as the tables used by the ELECTRICAL statement The extracted sheet resistance for the deposited layer does not correspond exactly to the resistivity specified during deposi tion Deposition of one material on top of another can cause a third material to be added between them This happens when titanium is deposited on silicon for example a layer of TiSi is inserted Insertion of extra layers is specified with the REACTION statement see page 3 239 Diffusion of impurities during a deposition step is not simulated even though a temperature may be specified Confidential and Proprietary S4 1999 2 Section 3 3 Process Steps TSUPREM 4 User s Manual ETCH The ETCH statement is used to remove portions of the current structure ETCH MATERIAL lt c gt SILICON OXIDE OXYNITRI NITRIDE POLYSILI PHOTORES ALUMINUM TRAPEZOI THICKNES lt n
70. ntrations are to be saved in TSUPREM 4 and WAVE output files Default true CHEMICAL logical Specifies that chemical impurity concentrations are to be included in the WAVE output file Default false DEFECT logical Specifies that point defect concentrations are to be included in the WAVE output file Default false OXID logical Specifies that oxidant concentrations oxidation flow rates and stresses if available are to be included in the WAVE output file Default false Synonyms STRESS MISC logical Specifies that miscellaneous solution values are to be included in the WAVE output file At present this includes diffusivities of impurities and point defects Default false S4 1999 2 Confidential and Proprietary 3 67 Section 3 2 Device Structure Specification TSUPREM 4 User s Manual Description The SAVEFILE statement writes mesh and solution information into a file in one of several formats If no format is specified a TSUPREM amp 4 structure file is cre ated TSUPREM 4 structure files can be read with the LOADFILE or INITIALIZE statements The mesh can be scaled or flipped about the x axis as the structure is written or when it is read Scaling and flipping during writing only affect the saved structure and do not affect the structure used by subsequent simu lation steps TSUPREN 4 Files The silicon substrate orientation last processing temperature current oxidation model and current point defect model are saved in
71. of one so the PRINT state ment only uses material boundaries to define layers Further when the value 1 0 is integrated over each layer the result is just the layer thickness The following statement specifies the title to be used on the next plot SELECT TITLE Final N Channel Structure Because no Z value is specified Z 0 is assumed and any attempt to print or plot solution data uses the value zero Confidential and Proprietary 3 123 Section 3 4 Output TSUPREM 4 User s Manual PRINT 1D The PRINT 1D statement prints the value of the selected expression along a line through the structure It can also print layer thickness and integrated doping infor mation PRINT 1D X VALUE lt n gt Y VALUE lt n gt MATERIAL lt c gt SILICON OXIDE OXYNITRI NITRIDE POLYSILI PHOTORES ALUMINUM MATERIA lt c gt SILICON OXIDE OXYNITR NITRIDE POLYSIL PHOTORE ALUMINU AMBIENT REFLECT SPOT lt n gt LAYERS X MIN lt n gt X MAX lt n gt Parameter Type Definition X VALUE number The x coordinate of a vertical section along which values are to be printed Units microns Default 0 0 Y VALUE number The y coordinate of a horizontal section along which values are to be printed Units microns Default none MATERIAL character Print values in the named material at the interface with the other specified material Default none SILICON logical Print values in
72. particular that the statement ETCH OXIDE TRAP does not implement a selective etch of oxide but rather defines a region geometrically in which all exposed oxide is removed Etching with Taurus Topography S4 1999 2 The TOPOGRAP parameter invokes Taurus Topography with the specified com mand input file The command input file contains Taurus Topography com mands describing one or more processing steps to be simulated by Taurus Topography It should not contain the INITIALIZE or STOP statements The values of variables set with the ASSIGN DEFINE and EXTRACT statements are substituted in the Taurus Topography command input file In addition to variables set explicitly by you if the THICKNES parameter is set on the ETCH statement then its value is assigned to the variable THICK prior to substitution If Confidential and Proprietary 3 95 ETCH Section 3 3 Process Steps Examples 3 96 TSUPREM 4 User s Manual the variable THICK is assigned in this way it will be unset after the ETCH state ment even if it was set by you previously This allows parameter values such as etch thickness to be passed to Taurus Topography The most recent mask file specified in the TSUPREM 4 input file is passed to Taurus Topography for use in masked etch steps By default Taurus Topography is called by requesting that the command topography be executed by the operating system but if the environment vari able S4TERRAIN is set its
73. pplied to the mesh when writing TSUPREM amp 4 struc ture files All coordinate values saved in the file are multiplied by this value The SCALE parameter does not affect the structure used by subsequent simula tion steps Units none Default 1 0 Specifies that the structure should be reflected about y 0 when writing TSUPREM 4 structure files All y coordinates are multiplied by 1 as they are written to the file FLIP Y does not affect the structure used by subsequent simulation steps Default false Specifies that the output file be saved as a TIF Technology Interchange For mat file Default false The version of TIF to be used for saving the file The default is to use the latest version of TIF a value of 0 produces files compatible with version 6 0 of TSUPREM 4 Units none Default 1 2 0 Confidential and Proprietary 3 65 Section 3 2 Device Structure Specification TSUPREM 4 User s Manual Parameter DEPICT MEDICI POLY ELE ELEC BOT MINIMOS5 X MASK S HALF DEV FULL DEV X MASK D X CHANNE X MIN 3 66 Type logical logical logical logical logical number logical logical number number number Definition Specifies that the output file is a formatted file that can be read by Avant TCAD s Taurus Lithography programs Default false Specifies that the saved output file is a formatted file that can be read by the Medici device simulator The output fil
74. r I CONC or I RESIST are used to specify the concentra tion or resistivity respectively associated with the named impurity The resistivity is calculated from tables of mobility as a function of doping con centration These tables are described in Chapter 2 Initial Impurity Concentra tion on page 2 10 Although the source of the grid read or generated and the specification of doping are independent the doping specification is normally used when a grid is gener ated but not when a grid is read from a file 1 The following statement reads in a previously saved structure in file oldstr INITIALIZE IN FILE oldstr 2 The following statement generates a rectangular mesh and initializes the structure with a boron doping of 10 5 cm INIT lt 111 gt X ORIENT 211 BORON 1e15 The orientation of single crystal silicon regions are lt 111 gt while the x axis points in a lt 211 gt direction 3 The following statement generates a mesh and initializes the structure to con tain arsenic with resistivity of 20 ohm cm INIT IMPURITY arsenic I RESIST 20 Note The conversion from a resistivity to a concentration is based on Masetti s mobility table while the calculation of electrical characteristics in the ELECTRICAL statement uses the same mobility table as in Medici Thus the sheet resistances of the initial structure given by the EXTRACT statement do not correspond exactly to the resistivity specified on the INITIALIZE s
75. rdinates of the plot Units none Default 2 ROW logical Specifies that the format of IN FILE is row wise Default false X ROW number The index of the row line in the file specified by the IN FILE parameter that contains the horizontal coordinates of the plot Units none Default 1 3 130 Confidential and Proprietary S4 1999 2 TSUPREM 4 User s Manual PLOT 1D Parameter Type Definition Y ROW number The index of the row line in the file specified by the IN FILE parameter that contains the vertical coordinates of the plot Units none Default 2 X LABEL character The label of the horizontal axis for X COLUMN data in the IN FILE file Default Distance microns Y LABEL character The label of the vertical axis for Y COLUMN data in the IN FILE file Default if the SELECT statement is defined LABEL in SELECT otherwise Concentration em y X SHIFT number The offset by which X COLUMN data are shifted when reading IN FILE file Units the same as for the X COLUMN data Default 0 0 Y SHIFT number The offset by which Y COLUMN data are shifted when reading IN FILE file Units the same as for the Y COLUMN data Default 0 0 X SCALE number The scaling factor by which X COLUMN data are multiplied when reading IN FILE file Units none Default 1 0 Y SCALE number The scaling factor by which Y COLUMN data are multiplied when reading IN FILE file Units none Default 1 0 Y LOG logical Specif
76. re device is shown or more than one variable can be conveniently plotted By default the limits of the x axis extend to the edges of the structure and the y axis is scaled according to the minimum and maximum values of the selected value over the entire structure The quantity to be plotted must be defined by a preceding SELECT statement The type of graphics device must be set either with an OPTION statement or through use of a suitable default See OPTION on page 3 33 and Appendix B If two materials are specified e g OXIDE SILICON a cross section is plotted in the first material e g oxide at the interface with the second material e g sil icon Note that OXIDE SILICON produces different results from SILICON OXIDE For interface plots the points along the interface are sorted by their x coordinates specifying interfaces containing vertical segments or reentrant angles may not produce useful plots Line Type and Color The LINE TYP parameter specifies the dashed line type for plotting the data Line type 1 is solid while types 2 through 7 are dashed lines with increasing dash sizes Types 8 through 10 produce more complicated patterns of dashes The COLOR parameter specifies the color for plotting the data Color 1 is the default and produces a line that contrasts with the background color e g black on white or white on black The COLOR parameter has no effect on monochrome displays The colors produced by
77. ser s Manual The SELECT statement evaluates a quantity to be printed or plotted It is also used to specify plot titles and axis labels SELECT Z lt c gt TEMPERAT lt n gt LABEL lt c gt TITLE lt c gt Definition A mathematical expression defining the quantity to be printed or plotted If the expression contains spaces it must be enclosed in parentheses Default 0 The temperature at which the solution is to be evaluated Units degrees Celsius Default last specified temperature or 800 The label to be used on the y axis of a one dimensional plot or the z axis of a three dimensional plot Default the expression given by Z The title to be used on plots Default the name and version number of the program The SELECT statement evaluates the quantity to be displayed by the CONTOUR PLOT 1D PRINT 1D PLOT 2D and PLOT 3D statements or to be extracted by the EXTRACT statement No solution data can be printed or plotted until this statement is specified The values calculated by a SELECT statement are used until another SELECT statement is specified If the solution changes a new SELECT statement is given in order for the new values to be printed or plotted The Z parameter specifies a mathematical expression for the quantity to be plot ted The following solution values can be used in the expression provided that the solution is available antimony antimony concentration atoms cm arsenic arsenic conc
78. sidewalls have an angle of 90 Units degrees Default arctan THICKNES UNDERCUT if THICKNES and undercut are both specified 90 otherwise UNDERCUT number The distance that the etch extends under masking layers when the TRAPEZOI parameter is specified Units microns Default THICKNES tan ANGLE for ANGLE lt 90 0 otherwise LEFT logical Etch material to the left of the specified position Default false RIGHT logical Etch material to the right of the specified position Default false P1 X number The x coordinate of the first point used when LEFT or RIGHT is specified Units microns Default 0 0 P1 Y number The y coordinate of the first point used when LEFT or RIGHT is specified Units microns Default a point above the top of the structure P2 X number The x coordinate of the second point used when LEFT or RIGHT is specified Units microns Default the value of P1 X P2 Y number The y coordinate of the second point used when LEFT or RIGHT is specified Units microns Default a point below the bottom of the structure START logical The point X Y is the first point in a series defining the region to be etched Default false CONTINUE logical The point X Y is the next point in a series defining the region to be etched Default false DONE logical The point X Y is the last point in a series defining the region to be etched Default false Synonyms END ISOTROPI logical Specifies removal of material that lies within TH
79. specified material at the interface with polysilicon Default false PHOTORE logical Print values in the other specified material at the interface with photoresist Default false ALUMINU logical Print values in the other specified material at the interface with aluminum Default false AMBIENT logical Print values in the other specified material at the interface with the exposed surface if any Default false Synonyms EXPOSED GAS REFLECT logical Print values in the other specified material at the interface with the reflecting boundary if any Default false SPOT number Print the coordinate along the cross section at which the selected quantity equals the specified value Units units of the selected quantity Default none LAYERS logical Report the integral of the selected quantity over each layer of the device structure Default false X MIN number The minimum position along the cross section to be printed Units microns Default none X MAX number The maximum position along the cross section to be printed Units microns Default none S4 1999 2 Confidential and Proprietary 3 125 Section 3 4 Output TSUPREM 4 User s Manual Description The PRINT 1D statement prints the values of the selected quantity along a cross section through the device cross sections are defined as vertical or horizontal by the X VALUE and Y VALUE parameters respectively along the interface between two materials or along a
80. sure of the ambient gas at the start of the step Units atmospheres Default the pressure specified in the corresponding AMBIENT statement or 1 0 if flows are specified P RATE number The time rate of change of the ambient gas pressure Units atmospheres minute Default 0 0 P FINAL number The ambient gas pressure at the end of the step Units atmospheres Default PRESSURE HCL number The percentage of chlorine present in the ambient gas Units percent Default value calculated from F HCL or specified on AMBIENT statement D RECOMB number The fraction of Frenkel pair implant damage remaining after initial recombina tion Units none Default 0 0 3 110 Confidential and Proprietary S4 1999 2 TSUPREM 4 User s Manual Parameter Type MOVIE character DUMP number Description Ambient Gas Ambient Gas S4 1999 2 Parameters DIFFUSION Definition A string of TSUPREM 4 commands to be executed at the beginning of each time step Multiple input statements can be given separated by semicolons Default no commands executed Write a solution file after every DUMP time step The files are readable with the LOADFILE and INITIALIZE statements The names are of the form s lt time gt where lt time gt is the time in seconds from the start of the diffusion step Units none Default no intermediate solutions saved This statement specifies a diffusion step with or without oxidation Any impuri ties present in
81. tatement Confidential and Proprietary 3 61 Section 3 2 Device Structure Specification TSUPREM 4 User s Manual LOADF ILE Parameter Type IN FILE character SCALE number FLIP Y logical TIF logical DEPICT logical Description The LOADF ILE statement reads mesh and solution information from a file LOADF ILE IN FILE lt c gt SCALE lt n gt FLIP Y TIF DEPICT Definition The identifier of a structure file to be read Default none Synonyms INFILE A scaling factor to be applied to the mesh when reading TSUPREM 4 struc ture files All coordinate values are multiplied by this factor as they are read Units none Default 1 0 Specifies that the structure should be reflected about y 0 when reading TSUPREM 4 structure files All y coordinates are multiplied by 1 as they are read Default false Specifies that the input file is a TIF Technology Interchange Format file Default false Specifies that the input file is a formatted file written by Avant TCAD s Tau rus Lithography formerly Depict Default false The LOADFILE statement reads a mesh and solution from a file Either TSUPREM 4 or TIF structure files created with the SAVEFILE statement or Taurus Lithography structure files can be read TSUPREM 4 structure files can be scaled or flipped about the x axis y 0 during reading TSUPREN 4 Files 3 62 The silicon substrate orientation last processing temperature current oxidation
82. the background doping concentrations of the impurities specified Mesh Generation If IN FILE is not specified a rectangular mesh is generated If LINE statements have been specified for the x or y direction they are used along with any ELIMINATE BOUNDARY and REGION statements and the value of the RATIO parameter to generate the mesh in that direction If no LINE statements are speci fied for the y direction a default y mesh is generated If no LINE statements are specified for the x direction and WIDTH is specified a mesh of the requested width is generated with spacing given by DX Ifno LINE X statements are given and WIDTH is not specified the width is taken from mask information read with a preceding MASK statement if any Otherwise a one micron wide structure with a grid spacing of one micron i e one grid space wide is generated See Chapter 2 Grid Structure on page 2 2 for a complete description of the mesh generation process The locations of the generated grid lines are listed if LINE DAT is true Previously Saved Structure Files A mesh read from a file must be in either TSUPREM 4 format or TIF Technol ogy Interchange Format Meshes read from TSUPREM 4 files can be scaled or flipped about y 0 by specifying the SCALE or FLIP Y parameters respectively When a structure is read from a file the last processing temperature as well as the choice of silicon substrate orientation oxidation model and point defect
83. the wafer are diffused If the wafer is exposed to a gas predeposi tion and or oxidation can be performed If an oxidizing ambient is specified and the VISCOUS oxidation model is in effect reflow of surface layers occurs The duration of the step must be specified with the TIME parameter The ambient temperature must be specified with the TEMPERAT keyword unless CONTINUE is specified For linear ramping of the temperature specify either the ramp rate with T RATE or the temperature at the end of the step with T FINAL The ambient gas used during the diffusion step can be specified in one of two ways 1 Specify one of the DRYO2 WETO2 STEAM INERT or AMB 1 through AMB 5 parameters These select an ambient that has been predefined with the AMBIENT statement The DRYO2 WETO2 STEAM and INERT ambients are defined by the standard initialization file the AMB 1 through AMB 5 ambi ents must be defined by the user before they are used The predefined ambi ents include a default pressure and HCl percentage which can be overridden with the PRESSURE and HCL parameters respectively on the DIFFUSION statement 2 Define the ambient by specifying the flows of oxidizing O and H O and nonoxidizing Hz Nx and HCl species The flows can be specified as flow rates fractions or percentages but the units of all the flows in a single DIFFUSION statement are assumed to be the same Any O and H in the gas are assumed to react two
84. ult false AMBIENT logical Plot a cross section through the other specified material at the interface with the exposed surface Default false Synonyms GAS EXPOSED REFLECT logical Plot a cross section through the other specified material at the interface with the reflecting boundary if any Default false IN FILE character The identifier for the file containing the data to plot This file may contain exper imental data or data produced by the EXTRACT or ELECTRICAL statements Default none TIF logical Specifies that the format of IN FILE is TIF iv file from Medici Default false X AXIS character The quantity used for the horizontal axis when plotting data stored in a TIF file The label is automatically assigned with the string composite of the X AXIS and the unit associated with X AXIS ina TIF file Default none Y AXIS character The quantity used for the vertical axis when plotting data stored in a TIF file The label is automatically assigned with the string composite of the Y AXIS and the unit associated with Y AXIS ina TIF file Default none COLUMN logical Specifies that the format of IN FILE is column wise Default true X COLUMN number The index of the column in the file specified by the IN FILE parameter that contains the horizontal coordinates of the plot Units none Default 1 Y COLUMN number The index of the column in the file specified by the IN FILE parameter that contains the vertical coo
85. ult size to be used for rectangles and centered symbols Units cm Default 0 25 Synonyms C SIZE The color of the label text and the default color for rectangles centered sym bols and line segments Units none Default 1 The character string to be used to label the plot Default none Specifies that the character string is to start at the position given by X and Y Default true if neither CENTER or RIGHT is true Specifies that the character string is to be centered horizontally about the posi tion given by X and Y Default false Specifies that the character string is to end at the position given by X and Y Default false The dashed type of a line segment to be plotted before the label If LABEL is not specified the line segment is centered at the point given by X and Y Units none Default 1 The color of the line segment to be plotted before the label Units none Default COLOR The length of the line segment to be plotted before the label Units cm Default 4 SIZE Confidential and Proprietary 3 149 Section 3 4 Output Parameter SYMBOL C SYMBOL RECTANGL C RECTAN W RECTAN H RECTAN 3 150 Type number number logical number number number TSUPREM 4 User s Manual Definition The type of centered symbol to be drawn before the label This value must be in the range 1 to 15 Values of this parameter are associated with the following symbols Square Circle
86. use version 1 2 0 while older products including ver sion 6 0 of TSUPREM 4 use version 1 00 or version 0 which are equivalent as far as TSUPREM 4 is concerned Correct writing of a user defined material or impurity to a TIF file requires that a TIF NAME be specified when the material or impurity is defined MD INDEX must also be specified for materials Before other programs can read the saved TIF 3 68 Confidential and Proprietary S4 1999 2 TSUPREM 4 User s Manual Medici Files SAVEFILE file an entry corresponding to the TIF name must be added to the appropriate database mat dbs for materials or sol dbs for impurities Note Versions 6 1 and later of TSUPREM 4 can read TIF files created by ver sion 6 0 but version 6 0 cannot read TIF files created by versions 6 1 and later unless TIF VERS 0 is specified when the file is written The MEDICI parameter creates an output file that can be read by the Medici device simulator MEDICI structures can also be read by older versions of TMA PISCES 2B and by other versions of PISCES The POLY ELE and ELEC BOT parameters are not needed when creating files for Avant TCAD s device simula tors because these simulators allow the treatment of polysilicon and backside contacts to be specified an a MESH statement Correct writing of a user defined material to a Medici file requires that MD INDEX be specified when the material is defined see MATERIAL on p
87. ut listing file Default false The name of the impurity with which the initial structure is doped Default none The concentration of the specified IMPURITY in the initial structure Units atoms cm Default none The resistivity of the initial structure Units ohm cm Default none Specifies the material of the initial structure Default SILICON The uniform concentration or resistivity of antimony in the initial structure Units atoms cm or ohm cm Default 0 0 Synonyms SB The uniform concentration or resistivity of arsenic in the initial structure Units atoms cm or ohm cm Default 0 0 Synonyms AS The uniform concentration or resistivity of boron in the initial structure Units atoms cm or ohm cm Default 0 0 Synonyms B Confidential and Proprietary 3 59 Section 3 2 Device Structure Specification Parameter Type PHOSPHOR number CONCENTR logical RESISTIV logical Description TSUPREM 4 User s Manual Definition The uniform concentration or resistivity of phosphorus in the initial structure Units atoms cm or ohm cm Default 0 0 Synonyms P Specifies that the impurity concentration in the initial structure is given Default true Specifies that the impurity resistivity in the initial structure is given Default false The INITIALIZE statement sets up the mesh from either a rectangular specifica tion or from a previously saved structure file This statement also initializes
88. value is used instead It may be necessary for you to define other environment variables e g TERR_LIB for Taurus Topography to run correctly For additional details refer to the Taurus Topography Reference Manual 1 The following statement etches the nitride to the left of 0 5 u to a depth of 1 micron ETCH NITRIDE LEFT P1 X 0 5 P2 Y 1 0 Note that P1 Y defaults to a location above the top of the structure and P2 X defaults to the value of P1 X i e 0 5 2 This statement etches the oxide in the square defined by 0 0 1 0 1 1 0 1 ETCH OXIDE START X 0 0 Y 0 0 ETCH CONTINUE X 1 0 Y 0 0 ETCH CONTINUE X 1 0 Y 1 0 ETCH DONE X 0 0 Y 1 0 Material is removed only if there is an exposed oxide surface somewhere within the boundaries of the etch 3 The following statement calls Taurus Topography with the input command file PolyDep inp ETCH THICK 0 1 TOPOGRAPHY PolyDep inp References to THICK in the Taurus Topography input file are replaced with the value 0 1 Confidential and Proprietary S4 1999 2 Section 3 3 Process Steps TSUPREM 4 User s Manual DIFFUSION The DIFFUSION statement is used to model high temperature diffusion in both oxidizing and nonoxidizing ambients DIFFUSE is accepted as a synonym for the DIFFUSION statement DIFFUSION TIME lt n gt CONTINUE TEMPERAT lt n gt T RATE lt n gt T FINAL lt n gt DRYO2 WETO2 STEAM INERT AMB 1 AMB 2 AMB 3 AMB

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