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ACS - 2600 RTM User`s Manual

1. I_tar v_tar vd ACS2600RTM 900 01 Rev B December 2012 2 19 Section 2 HCl and NBTI ACS 2600 RTM User s Manual 2 20 Example Idsat TAR IATV V Drain 1 V Drain 1 1 0 VADD Purpose return the sum value of V1 V2 Format VADD V1 V2 Remark If V1 and V2 are all single data it will return the sum value If V1 and V2 are all data arrays with the same length it will return the sum arrays one to one sum If one is a single data and the other is a data array it will return the sum arrays every data of the array adds the single data VDIV Purpose return the result of V1 divided by V2 Format VDIV V1 V2 Remark If V1 and V2 are all single data it will return the results of V1 divided by V2 If V1 and V2 are all data arrays with the same length it will return the divided result of the arrays one to one result If one is a single data and the other is a data array it will return the divided arrays result every data of the array corresponds to the single data VGISUBMAX Purpose Extrapolates the gate voltage at the point of the maximum sub current of the MOSFET Format VMULT Purpose returns the product value of V1 multiplied by V2 Format VMULT V1 V2 Remark If V1 and V2 are all single data it will return the product value If V1 and V2 are all data arrays with the same length it will return the product arrays one to one product If one is a single data and the ot
2. Subordinate eeececes gt RIA AO ea Group 1 Master eeececee gt Shoshone 2 Subordinate porron gt Ii os r era Subordinate eeececee gt IEA Subordinate seeececece gt aia SS Group 2 GPIB Cables Ethernet Cables with hub or router Master seeececee gt ANA gt Subordinate process gt AAA Subordinate eeececee gt rae ae aa Subordinate postores gt Es ee J Group 3 In the multiple group GPIB or Ethernet connection scheme each group of instruments has a unique GPIB address or IP address Within a group there will always be a Master instrument and at least one Subordinate The Master node must be set to 1 and each instrument within a group must have a unique node number 1 64 For more information on how to setup the daisy chain TSP Link instrument network refer to the Series 2600B Reference Manual document number 2600B 901 01 1 4 ACS2600RTM 900 01 Rev B December 2012 ACS 2600 RTM User s Manual Section 1 ACS 2600 RTM SMU designation in ACS When ACS starts it will assign names for each SMU For an instrument configuration each SMU has a unique global name SMU1 SMU2 SMU3 etc Within each GPIB group or Ethernet group the SMU also has a local name the local name is used within the group These can be found on the hardware navigator in the Configure Hardware inter
3. gt Stress time Monitor time a Istress Maximum current Refer to the Max field in the breakdown settings window If the measured monitor current in a ramp step exceeds the Max setting the test flow for this device will exit the ramp test loop for the post ramp test and the device is considered to have failed the ramp Maximum charge Refer to the Max Q field the in the breakdown settings window If the calculated charge quantity exceeds the Max Q value the testing for this device will exit the ramp test loop for the post ramp test and the device is considered to have failed the ramp test Current factor Refer to Critical and x Pre in the breakdown settings GUI If Critical is selected and the monitor current is larger than the critical current the monitor current will be compared to the previous monitor current If the monitor is larger than the CM times the previous monitor current CM is the setting factor the device is considered to have failed the ramp test ACS2600RTM 900 01 Rev B December 2012 ACS 2600 RTM User s Manual Section 5 Voltage ramp Current slope versus voltage Refer to Critical I and Slope x Pre in the breakdown settings window If Critical is selected and the monitor current is larger than the critical current the monitor current versus voltage slope will be compared to the previous slope If the slope is larger than the SM times of the previous slope SM i
4. 1000 R Q 800 Section 7 Electromigration ACS 2600 RTM User s Manual Instrument connection The Iso_EM test uses a two terminal or a four terminal resistor device For two terminal resistors current is forced and voltage is measured at the positive terminal and the negative terminal is biased at OV For four terminal resistors current is forced at the Force Hi terminal the Force Lo terminal is set to OV the Sense Hi terminal is set to OA and voltage is measured between Sense Hi and Sense Lo Figure 87 Two terminal and four terminal resistor device Sense Hi Sense Lo Positive A A A Negative Force Hi Force Lo Two terminal resistor Four terminal resistor The test uses Series 2600B or Series 2600 SourceMeters The SourceMeters can be setup as different groups GPIB or Ethernet for parallel testing Within each group you can also setup multiple sub devices for sequential or parallel testing In a parallel test each sub device will be set as a sub group DTNS Group The SourceMeters in a connection scheme must have the same firmware The 2600B SourceMeters and the 2600 SourceMeters for instance the A and non A versions cannot be used together A typical connection scheme is shown in the next figure Figure 88 A typical instrument connection scheme GPIB Cables Or TSP LINK Subordinate Node3 Subordinate Node3 eS otiocoe HS a urrsarrrrrnrrrnrrnrnsnn dno19 SNLG Buo
5. Conver Factor used in the Convergence section in phase 2 The recommended range of values for this parameter is 1 3 Error Band C if temperature is within the target temperature for instance target temperature Error Band then phase 2 ends and phase 3 begins Isource A source current on the DUT before phase 3 Isource Phase3 A source current on the DUT in phase 3 Figure 101 General Settings GUI for Poly Heater General Settings Test Mode E Constant P T C Constant I Material al TCR Ref Temp C 0 0033 Ref Temp C 26 0 Chuck Temp C 26 0 Jchuck A cm2 0 001 Jstart A cm2 0 001 Current Muki Phase1 1 1 Temp Step Phase2 C 10 0 Conver Factor 2 0 Error Band C 1 0 Isource A 0 001 Isource Phase3 A 0 001 8 8 ACS2600RTM 900 01 Rev B December 2012 ACS 2600 RTM User s Manual Section 8 Poly heater Device and SMU settings The device and SMU settings are all set at the device level For example all of the devices and SMUs that are assigned in the device level of the test tree such as the Group No Dev No SMU and Terminal are shown in the next figure Area cm2 the cross section area of the poly heater used to calculate the heat current from the current density setting Compl compliance limit value For the Force Hi Sense Hi Sense Lo Heat Hi and Heat Lo terminals it is the voltage compliance units are volts for the Force Lo terminal it is the curr
6. The On Seq and Off Seq enable the SMU output to turn on or off on in a certain sequence for a special device For example if depletion mode for an NMOSFET should be applied a negative voltage on the gate first will set the device to off The Copy 1st to All function is used to copy the settings of the first sub device to all of the other sub devices ACS2600RTM 900 01 Rev B December 2012 ACS 2600 RTM User s Manual Section 2 HCl and NBTI Measure settings The Measure tab is used to setup the measure phase test steps and the exit criteria Note that each tab has settings for the related sub device The Measure settings tab contains similar settings as the Pre Stress Tests tab Refer to the description of the Pre Stress Tests for details Figure 28 Measure phase settings Settings Measure post Stress Tests event oavexa Sub de vice Exit criteria 10 Name Unit Enable Target Shift 1 VI MEASI meas0 VT_MEASI V Absolute 2 LGate_1_measi LGate_1 A a Percentage 3 LOrin_t_meast Lonni A 1 Absolute Parameter properties degradation targets This GUI is used to setup the exit criteria for the measured or calculated parameters The parameter change will be tracked after each stress phase and if the parameter shifts to a target level the test for the device will exit Enable Target select this option to enable the parameter to exit device testing if the parameters are reached Shift select the method to d
7. When the Series 2600B System SourceMeter instruments are referenced it also includes the Series 2600A System SourceMeter instruments since these two series of instruments are fully interchangeable However the following instruments are not supported in ACS Basic Model 2604B Model 2614B and Model 2634B Section 1 ACS 2600 RTM ACS 2600 RTM User s Manual WLR and ACS 2600 RTM overview 1 2 The wafer level reliability WLR test is used to perform a series of reliability tests to the wafer level devices prior to packaging These tests usually apply certain stresses voltage current or temperature to the device and monitors the parameters that change over a period of time until reaching the defined failure condition or maximum testing time The degradation rate of the device or material can then be obtained through statistical analysis of the test data The ACS 2600 RTM package is a group of reliability tests for the Series 2600B and Series 2600 SourceMeters These tests operate on a single device or multiple devices sequential or parallel The tests are designed for but not limited to silicon based CMOS wafer process technologies The ACS 2600 RTM tests are referred to as 2600 based reliability test modules RTM in ACS Additionally there are other types of modules in ACS interactive test module ITM python test module PTM C language test module CTM and script test module STM These modules can also be used in a S500
8. Device Rel A pattern_1 MN ya pines NBTILFAST_SWI 2 HOME M e CUSTOM_26 i C Metal La Al Sequential C Parallel ae ali vs 2 Cancel ACS2600RTM 900 01 Rev B December 2012 ACS 2600 RTM User s Manual Section 1 ACS 2600 RTM Test module settings The 2600 based RTM tabs that are used for configuration are shown in the next figure Figure 10 RTM configuration tabs Indicate the test module type gf li orn y Pas P and name Sequential or Parallel Three tabs of settings or data i so dl id lez el y Main settings interface There are three tabs used for configuring the 2600 based RTM e Definition settings for stress measure timing exit criteria etc These settings define the test flow and data acquisition Different RTM tests have their own Definition tab Note that some tests have multiple tabs for definition settings e Data shows the measured data in the table plot or both Sort the data column sequence VgID Linear t t KEITHLEY I SS Sa EEES 3 000000e 0044 614520e 004 2 616640e 009 1 836580e 004 1 9000006 00 33358308 011 6 4127408 0112 0000008 0041 000000 001 3 f 1 4492708 0042 9492408 009 1 869450e 001 1 600000e 0667000 0 1 Z 6 309600 004 1 895210 0043 4109000 009 1 8976500 004 1 500000e00 _ 1 2515108 010 1 586680e 01 2 000000 0045 000000e 001 8 A AN ESTA ae E SE iD DEE ide COUTO 7 j fi 7eseoe010 2 200000e1 2 000000 006 00000
9. Sets the gate stress voltage value Pre Post V Only available for the gate terminal Sets the gate pre test and post test bias voltage values SILC Only available for the gate terminal Sets the SILC test bias voltage value or sweep voltages Double clicking the cell will enable a dialog box to open where you can change the sweep voltage settings see next figure e Start Value sweep start voltage units are volts e Stop Value sweep stop voltage units are volts e Num of Points the number of points in the sweep e Vcheck the measured gate current when under Vcheck bias is defined as Isilc Figure 62 Device and SMU settings Define Sweep Test r Definition gt Start Value 0 00 Stop Value 1 00 Num of Points 11 Vcheck 0 33 OK Cancel Vuse_1 and Meas the Vuse_1 is the value at the measure phase If the check box for Meas is selected the current will be measured Vuse_2 and Meas the Vuse_2 is the value at the measure phase If the check box for Meas is selected the current will be measured ACS2600RTM 900 01 Rev B December 2012 4 13 Section 4 Time dependent dielectric breakdown ACS 2600 RTM User s Manual Failure determination Initial test The TDDB_CVS testing begins by performing a pre test The pre test applies a gate bias voltage in the Pre Post V and measures the gate current as Ipre If the calculated gate current density exceeds the high limit Jmax or the low li
10. auto_update_manual_run_plot 1 Automatically update the graphs in the Real time Plot window auto_update_manual_run_plot 0 Manually update the Real time Plot using the Refresh function see detail below Export the csv file by using the Export data function see detail below Abort operation or unexpected crash Secure the tmp data above and convert to a csv or db file see detail below In Automation the data results can be logged as a csv db or kdf file However some long term tests need to analyze data while the test is still running ACS provides a Real time Plot Current Site 1 2 see the next figure that displays the selected test results For more details about the real time plot refer to ACS Reference manual document number ACS 901 01 By default the plot or data in real time will automatically update a certain period of time However similar to the manual update it can be set to manually refresh In the file that is located in the following location ACS KATS ACS _setting ini the setting for the auto_update_realtime_plot 0 enables a manual update Figure 15 Real time plot MN Real time Plot Current Site C1 2 Pista DE iphoto Baal On HCI_GROUP HcI_GROUP2 Click to update data or plot 1 888342e 001 3 776685e 001 5 665027e 001 1 916054e 001 2 410918e 001 2 299986e 001 3 832108e 001 4 821837e 001 4 599973e 001 5 748162e 001 7 2
11. December 2012 ACS 2600 RTM User s Manual Section 7 Electromigration Exit criteria When the measured or calculated result exceeds the exit criteria the test will end and the fail time will be logged The following defines the exit criteria e Resistance criteria in each phase either the absolute value or the shift Refer to the Rchuck Rshift Phase1 Rshift Phase2 and Rshift Phase3 settings e Maximum source current Refer to the lexit setting e Voltage compliance Refer to the Compl setting e Maximum time Refer to the Max Time setting e Maximum count of data Refer to the Max Count setting The next table lists the failure modes of the lso_EM which will be logged as a test fail Failure mode Comments 1 Calculation error Reach maximum time or maximum count of data Resistance fail Initialization phase fail Reach voltage compliance Reach maximum source content BAjoOo n 0 ACS2600RTM 900 01 Rev B December 2012 7 9 Section 7 Electromigration ACS 2600 RTM User s Manual Data recording The test results data are displayed on the Data tab and will be logged as a kdf db or csv file if run in the Automation mode Data for multiple Groups are displayed using multiple tabs within the Data tab The output data for different sub devices is distinguished by the parameter names The output 7 10 ACS2600RTM 900 01 Rev B December 2012 parameters for one group are in the
12. F S 3 3 2 eccsecce gt MIU gt En me aa 3 5 2 Subordinate Node3 o Subordinate Node3 78 E 3 0 aood O Subordinate Node4 oO 3 3 wc otjiocose EE aroup 1 Group 2 e e eee J Parallel running among GPIB or Ethemet Group Due to limited memory space and instrument communication speed the connection scheme requires care in setting the sample interval in order to avoid memory and logging errors A connection scheme with more instruments requires a longer sample interval However if you are using proper data compression the logged data will be largely decreased but it is still able to demonstrate the whole curve and avoid the limited memory problem 4 2 ACS2600RTM 900 01 Rev B December 2012 ACS 2600 RTM User s Manual Section 4 Time dependent dielectric breakdown Test flow The TDDB_CVS test flow is based on the JESD92 standard The parameters are also defined with reference to JESD92 The test flow is shown in the next figure If a sub device fail during the pre test or breaks down during the stress measure sequence all of the SMUs related to the sub device will be set output off The output off mode is High_Z high impedance which means the output relay is open The High_Z mode is automatically set to used SMUs For unused SMUs if you want to set output off mode to High_Z you need to select Tools gt Preferences gt Misc select H
13. 01 Rev B December 2012 2 21 Section 2 HCl and NBTI 2 22 ACS 2600 RTM User s Manual VTLINGM Purpose extract the threshold voltage from the maximum transconductance gmmax Return the Vg intercept of the linear fit of ld versus the Vg at the maximum gm point Format VTLINGM 1_DRAIN V_GATE Figure 39 VTLINGM parameters Returned Value VTSATGM Purpose extract the threshold voltage of the saturation region Return the Vg intercept of the linear fit of the sqrt abs Id versus the Vg at the maximum slope point Format VTSATGM I_DRAIN V_GATE Figure 40 VTSATGM parameters Sqrt abs Id Linear fit at the maximum slope Returned Value ACS2600RTM 900 01 Rev B December 2012 ACS 2600 RTM User s Manual Section 2 HCl and NBTI Data recording The test result data is displayed in Data tab and will be logged as a kdf db or csv file if in Automation mode The data for multiple groups is displayed in multiple tabs in the Data tab The output data for sub devices is distinguished by the parameter name suffixes The output parameters for one group are shown in the next table Parameter Unit Comment Time_str_ lt sn gt S The accumulated stress time Time_total_ lt sn gt S The total time including measure phase _ lt pad gt _moni_ lt sn gt A The measured current in monitor stress phase for example _Gate_1_moni_1 V_ lt pad gt _ lt test step name gt _ lt
14. A E AT EE AE 8 6 TIMING SEN Sennaa RAKE AA RAR a RS 8 7 General SOMINGS sinisin mein meshes E R N Mecca E E E R RERNA 8 8 Devices and SIMU Settings carlo a e a e aa E EER 8 9 A E 8 10 Data OCON enoni E lain dace aathuceeclsdaceagy tdecaiadaeu ua dee nadeear ae 8 11 ACS2600RTM 900 01 Rev B December 2012 iii Section 1 ACS 2600 RTM In this section DREGE NS HOM adan iasid 1 1 WLR and ACS 2600 RTM overvieW cccccceseseeeeeeeeeeseeneeees 1 2 Instrument connection SCHEME cccccceseeseececeeeeeaneseeeeeeees 1 3 Sequential And parallel cocomosssrscai scsi 1 6 ACS 2600 based RTM general SettidgS ooooonoccccnonocicincccncnn 1 7 Data analysis aaa a ibid 1 19 Introduction If you have any questions after reviewing this information contact your local Keithley Instruments representative or call one of our applications engineers at 1 888 KEITHLEY 1 888 534 8453 within the U S and Canada You can also visit the Keithley Instruments website at www keithley com for updated worldwide contact information Also for further reference on ACS software refer to the Automated Characterization Suite ACS Reference Manual document number ACS 901 01 Additionally refer to the supplied documentation that is located on the Keithley Instruments CD ROM that was shipped with your purchase You can also visit the Keithley Instruments website at www keithley com to search for updated information by model number NOTE
15. Figure 55 Breakdown settings Data compression setting ACS will log the compressed data according to the following settings see the next figure This function can reduce the total amount of data without losing the parameter change tracking information Figure 56 Data Compression setting 4 8 ACS2600RTM 900 01 Rev B December 2012 ACS 2600 RTM User s Manual Section 4 Time dependent dielectric breakdown Igate Shift if the Igate shifts the Shift Rate percentage and this parameter is selected it will be logged e Shift Rate if the current measured data change ratio exceeds the Shift Rate percentage as compared to the previous logged data the data will be logged e Lowest Line A if the absolute value of the measured data is lower than this value Igate Shift will not be effective When current is near the noise level this function will be effective to prevent all of the measured data from being logged Time When this is selected the logged data will be time compressed For Linear or Log only one option can be selected e Linear Every Constant Time s seconds one data point is logged The data is the mean value of the time period e Log Every decade a Points Decade number of data points are logged The data is the measured value at each time point Start s before the time of stress the Data Compression will not be effective The data before this time will be logged Figure 57 Data compression diagr
16. For the gate double clicking the cell enables a dialog box to open that is for the stress ramp segment settings For other terminals select GND or OPEN GND force OV OPEN force OA e Istart start the current of the ramp e Imax stop the maximum current of the ramp e multF the factor of each ramp step The next ramp current after the Istress is IstressxmultF e Stress Intv s stress interval time between two ramp steps Monitor monitors the voltage during each ramp step this is always selected Compl the current compliance limit CompV the voltage compliance limit Figure 83 Device and SMU settings for JRamp TDDB_CCS Checked Group No Dev No W um L um SMU Terminal Pin No Stress Setting Monitor Compi Cad pee Do REE e O A o a Number of Ramp Segments i s alos Breakdown settings When the Breakdown Settings function is selected a dialog box containing all of the breakdown criteria settings opens see next figure Figure 84 Breakdown settings for JRamp TDDB_CCS Opt pre test pre post check Iinit Vuse multV Ibound Ibound jes a Lowest V Lowest V hesola 0 9 x m ne a 1 0 0 9 5 y 0 1 6 8 ACS2600RTM 900 01 Rev B December 2012 ACS 2600 RTM User s Manual Section 6 Ramped current Opt pre test if selected the test will run the optional pre test at the beginning of the flow pre post check if selected the test will check the results of the pre test
17. N for NMOS P for PMOS Stress Setting For the gate double clicking the cell enables a dialog box to open that is for the stress ramp segment settings For other terminals select GND or OPEN GND force OV OPEN force OA e Number of Ramp Segments up to five can be specified e Start V start voltage of the ramp segment It is the same as the stop voltage of the previous segment e Stop V stop voltage of the ramp segment It is the same as the start voltage of the next segment e Ramp Rate V s the voltage ramp rate of the ramp segments Each segment has its own ramp rate e Stress Intv s stress interval which is the time between two ramp steps All the stress intervals are the same for all segments e Ramp Step V calculated from the ramp rate and stress interval Monitor monitors the current during each ramp step this is always selected Vpre the applied voltage for the pre ramp test Vpost the applied voltage for the post ramp test Vuse the voltage applied when the Monitor at Vuse is selected Ibox when the Output Vbox at Ibox is selected The log for the step voltage Vbox when the current exceeds the value for the first time Compl the current compliance limit value Figure 72 Device and SMU settings for VRamp Checked Group No Dev No W um L um Dev Type SMU Terminal Pin No Stress Setting Monitor Vpre Vpost Vuse Ibox Compl SMUI Gate 1 1 00 10 00 0 10 0 1 500 1 500 1 500 0 01 2 0
18. Pre stress test Pre stress test eet the pre stress Exit test for the exit criteria 4 failed device ly First measure phase TO eet the measure phase Exit test for the extt criteria failed device i 5 Exit test for the Compliance failed device N Stress delay eet the measure phase Exit test for the exit criteria failed device Stress measure sequence end Pre stresstest Post stress test 2 4 ACS2600RTM 900 01 Rev B December 2012 ACS 2600 RTM User s Manual Section 2 HCl and NBTI The Pre Stress Tests are used to verify the characteristics of the device and are used to select the good device for the next test The stress measure sequence is the main loop of the HCI NBTI test It will apply voltage stress to the device and extract the device parameter changes The Post Stress Tests are used to verify the characteristics of the device after the HCI NBTI test The waveform of the HCI NBTI test is in the next figure Figure 20 Waveform diagram of HCI_NBTI Monitor cod sal V Stress sind ya Sal Siaa fue Bini Sweep Spot Sample Sweep Spot Sample A Aid e Pre_stress TO Measurement Measurement Post_stress Measurement Measurement gt Stress Measure sequence ACS2600RTM 900 01 Rev B December 2012 2 5 Section 2 HCl and NBTI ACS 2600 RTM User s Manual Settings Several device types can be selected in the device level of the test tree For a single device only the nMOSFET and
19. TSP dalla id LINK Subordinate Node 2 Subordinate Node 2 e2esjooce eases lt gt OINSIGTUBH PENES rs Ps a Subordinate Node3 Subordinate Node3 aa 2eeeccee gt eat oh i yy irrrrnrrrsrnrrrrnrsrn s dno19 SNLG Buowe Bumuna jo pese d eetocoe Aa Subordinate Node 4 Subordinate Node 4 dno19 SNLG Buowe Buiuuns ape sed cececee gt eeeciecece gt Pi EA Parallel running among GPIB or Ethernet Group 1 6 ACS2600RTM 900 01 Rev B December 2012 ACS 2600 RTM User s Manual Section 1 ACS 2600 RTM Sequential versus parallel When you add a 2600 based RTM you will have to choose either Sequential or Parallel see the figure named DTNS group run in sequence These settings determine the running mode within a group GPIB or Ethernet and note that the mode between groups is always parallel Parallel testing means that each sub device runs all tests at the same time and sequential testing means that the sub devices run only one test at a time Example 1 The connection scheme in the figure named GPIB or Ethernet connection scheme has 12 instruments in three groups and each group has one master with three subordinates The three groups will run tests in parallel and within each group four instruments will run sequentially Example 2 The connection scheme in the figure named Sequential or parallel connection scheme has eight instruments in two groups a
20. _str_ lt sn gt V The ramped voltage level _ lt pad gt _str_ lt sn gt A Measured current at ramped voltage level in ramp step stress time _ lt pad gt _moni_ lt sn gt A Measured monitor current in ramp step monitor time Q_ lt pad gt _moni_ lt sn gt C Accumulated gate charge _ lt pad gt _post_ lt sn gt A Measured current in Post ramp test Vbox_ lt pad gt _ lt sn gt V The first ramp voltage when the current exceeds Ibox Veritical_ lt sn gt V The first ramp voltage when current exceeds Icrit Tbd_ lt sn gt S Breakdown time Vbd_ lt sn gt V Breakdown voltage Ibd_ lt sn gt A Breakdown current Qbd_ lt sn gt C Quantity of charge when breakdown Fail_mode_ lt sn gt Fail mode lt sn gt the number of the sub device lt pad gt pad name usually the gate in VRamp For example sub device 1 pad name Gate_1 the ramped voltage level is V_Gate_1_str_1 ACS2600RTM 900 01 Rev B December 2012 Section 6 Ramped current In this section Testunnciples ticos tren rarer rye rere 6 1 instrument CONMECUON ieiosiononsnarias ici id 6 2 TES ios 6 4 A O 6 6 Failure determinatOM saiswensccniaisisaidy vuabanadiussccteoabaanlanntaseasaaiaadea 6 9 Data recorrida lar AS 6 11 Test principle The ramped current JRamp test uses a ramped current stress applied to capacitors or gate oxides to characterize dielectric defects that appear at higher electrical fields The JRamp test is also able to perform the bounded JRamp test
21. ad 3 2 Measure phase NING sigas sli ea dre ola da 3 2 TO Messure ment cosomiajti ranma alas 3 3 nterdelay set es esas ants dap al a dera 3 3 Sal ple test step timing Setting esa 3 4 POSE AW gata iniiadaco a a Aaaa nA 3 5 Time dependent dielectric breakdown oooooncccccccconnnccnnnncconoccnonannnnncncnonennnnnnenennnnnons 4 1 TES MC UP Emainn E scecneaadusadeereeetoaatieoactacas 4 1 Table of Contents ACS 2600 RTM User s Manual Instrument connect aids 4 2 TOS MO Wisin A a A A AAA A 4 3 SITIOS miii 4 5 Stress measure time Sequence Setinas moco 4 6 A sass csucsacecedagatecsuieecs ESR REAALSE OSARA 4 7 DataiCOmpPressiOnsSe tingkesan a oe paces and hele clan 4 8 Dinamic MES sacos 4 10 Stress voltage compensation Seters a aeia a Leal 4 11 Hiah capacilante Mode tisini eee ee id 4 12 Device ane SMUSSHINOS sisas lo iia lio ia actes 4 13 Failure determinat ON ia is Aa dan 4 14 A perce ete Sree errr Cesare rrr eee enr er eee tere Pe Cera r mcrae nee ners erte 4 14 SESS measure SOG WSCC ranana a a eoane canes eaetaeee eee 4 14 A e 4 15 Failure ModE ascc ccoizssesfeacs sechensa sss cots te ceeds ceca sda chide aes aa a os aed eh naam c cde aN Es See cc caer asa oed 4 15 Data else gal ato Peeryertetenrererr rer ere tener o Tene terry er tr errr tte 4 15 bcc cl dle sppere peer rts tenenene peepee errre re here ee re sprererer ee eT ere sper eT erect rrr Te esr rer 5 1 TESEI ica ii rere cry rrr tree rs 5 1 nstument COMME CUOMN ica ad 5
22. or S530 parametric test systems All of the 2600 based RTMs are able to execute in sequential or parallel There are three 2600 based RTM test categories 1 Device reliability e HCI NBTI Hot carrier injection HCI and negative bias temperature instability NBTI HCI is a process where high lateral electrical fields in a MOSFET generate hot carriers high energy electrons or holes that can damage the MOS gate oxide interface and degrade the device s l V characteristics NBTI is primarily experienced by p channel MOSFETs and is thermally activated which may seriously affect a PMOS device reliability and manifests itself as an increase in the threshold voltage The test procedures of HCI and NBT are identical however they are stressed in different ranges e NBTI_FAST_SWITCHING For NBTI reliability testing This test is able to use a special method to minimize the recover time of a CMOS device when an effective measurement is implemented after one stress 2 Gate oxide e TDDB_CVS Time dependent dielectric breakdown TDDB under constant voltage stress CVS This mechanism causes the dielectric to breakdown and become electrically shorted after a period of operating time The TDDB test is used to obtain acceleration parameters of wear out time required to predict TDDB of the CMOS gate dielectrics e VRamp Voltage ramp VRamp test This test uses a ramped voltage stress on capacitors or gate oxide to characterize the defec
23. s during the stress phase after monitoring the compliance of the device is checked during the sample interval as long as the Stop on Compl is selected in the Stress Conditions section of the tab Low Range A the lowest current measure range that will be used in auto ranging ACS2600RTM 900 01 Rev B December 2012 2 11 Section 2 HCl and NBTI ACS 2600 RTM User s Manual 2 12 Stress conditions The Stress Conditions section for the stress setup lists all of the devices and SMUs that are assigned in the device level of the test tree Device No the device SMU and Terminal are all set at the device level W um and L um these are MOSFET device dimensions The W and L are set at the device level and are not available for editing here If they are under multiple devices more than one sub device W and L can be edited Note that W and L can be used as variables in formulas Stress V the stress voltage set for the pad during the stress phase Monitor monitors the current of this pad Stop on Compl select if you want the test to determine if the device branch on the pad is in compliance If in compliance the test for the device will exit Compl sets the compliance value unit is amps On Seq sets the sequence that the SMUs apply to the stress voltage The sequence of one SMU must vary from others Off Seq sets the sequence that the SMUs turn off the stress voltage The sequence of one SMU must vary from others
24. sources with high transient overvoltages Measurement Category II connections require protection for high transient overvoltages often associated with local AC mains connections Assume all measurement control and data I O connections are for connection to Category sources unless otherwise marked or described in the user documentation Exercise extreme caution when a shock hazard is present Lethal voltage may be present on cable connector jacks or test fixtures The American National Standards Institute ANSI states that a shock hazard exists when voltage levels greater than 30 V RMS 42 4 V peak or 60 VDC are present A good safety practice is to expect that hazardous voltage is present in any unknown circuit before measuring Operators of this product must be protected from electric shock at all times The responsible body must ensure that operators are prevented access and or insulated from every connection point In some cases connections must be exposed to potential human contact Product operators in these circumstances must be trained to protect themselves from the risk of electric shock If the circuit is capable of operating at or above 1000 V no conductive part of the circuit may be exposed Do not connect switching cards directly to unlimited power circuits They are intended to be used with impedance limited sources NEVER connect switching cards directly to AC mains When connecting sources to switching cards install protective devic
25. the heat current is calculated from the relationship of T R and T P and increased so that the temperature will increase almost linearly by AT This part ends when temperature achieves Ttest 2 AT e Convergence In this part the heat current is calculated from the relationship of T R and T P and forced so that the temperature will converge to Ttest quickly and smoothly D Stress Phase In this phase the temperature is kept constant by keeping power constant from the relationship of T P or the current is kept constant The R_dut value obtained at the beginning of this phase and a shift value determines the exit criterion E Post fail measurement After the device fails the R_dut will be measured again using the same current for Rdut Tchuck An example test results diagram is shown in the next figure 8 4 ACS2600RTM 900 01 Rev B December 2012 ACS 2600 RTM User s Manual Section 8 Poly heater Figure 98 Test results diagram for Poly Heater initialization temperature staircase Y gt convergence E stress ao Tehuck Leurce H H H Riu Phasel Phase Phase3 Rend Initialization Phase1 this phase begins at Tchuck and ends at about Tchuck 50 0C Temperature staircase Phase2 part 1 the temperature increases linearly to a certain temperature step until about Ttest 2xstep Convergence Phase2 part 2 the temperature converges to Ttest rapidly and smoothly Str
26. the same as the HCI NBTI test while the measure phase has a few more settings on the timing control Figure 42 NBTI_FAST_SWITCHING timing diagram inter Delay Monitor Fl Monitor 1 j Stress j I 44 44 44 44 44 Sweep Sample Sweep Sample Sweep Sample weep Samy Sweep Sample A TO Measurement Measurement Pre_stress Stress Measure sequence Post_stress Measurement Measurement 3 2 ACS2600RTM 900 01 Rev B December 2012 ACS 2600 RTM User s Manual Section 3 Fast NBTI TO Measurement The TO Measurement is the first measure phase in the stress measure sequence before the stress in applied In the NBTI_FAST_SWITCHING test the TO Measurement is optional see next figure Figure 43 Stress Settings for TO Measurement Pre Stress Tests Stress Settings Measure Post Stress Tests Stress Time Settings Stress Monitor Timing Comments Unear C log C List an io Fst Stress s o Hold Time s 0 0 US CU Sample Intervaks 1 0 Last s 100 0 Low Range A fies al Stresses fio afer e SSsSnE 1e 2 Voltage level at inter delay between test steps Inter delay The Inter delay is the delay time between two test steps in the measure phase An inter stress voltage level will be applied to the pad according to the settings see next figure The inter delay will not affect the TO measurement Figure 44 Measure phase of NBTI_FAST_SWITCHING and HCI_NBTI Measure phase gt Inter Delay bias
27. the selected test step Apply to All applies the current settings to all of the sub devices Up and down arrows move the selected test step up or down as needed In the Pre Stress Tests parameters you can make changes as needed A Points the amount of data points measured For a sample test it is one or more than one log the average value For a sweep it must be more than one B V_ lt pad gt set the bias voltage to the specific pad the unit is volt for example V_Gate_1 is 1 5 apply 1 5V bias to Gate_1 pad If the test is a sweep test the setting value should be two values separated by a comma for example 0 2 This indicates the sweep start voltage is 0 and the stop voltage is 2 Also the global variable can be set as an input C l _ lt pad gt select to measure the current of the specific pad the unit is amp D Formula double click the cell to open a dialog box for adding formulas which extract parameters from the forcing values and measured values E Timing double click the cell to open a dialog box for the timing settings The Pre Stress Tests setting tab is shown in the next figure Each sub device has its own tab for the Pre Stress Test settings The sub device is defined at the device level of the Test tree Figure 22 GUI settings for the sub device Pre Stress Tests stress Settings Measure Post Stress Tests Sub device ACS2600RTM 900 01 Rev B December 2012 2 7 Sec
28. which indicates each stress period during the stress phase Linear the stress list is a linear distribution and indicates the total number of stresses The values are automatically generated using the First Stress and Last Stress Log the log data is indicated in the Stress List distribution and the number of values in the list is indicated in each decade of the Stresses Decade The values are automatically generated using the First Stress Last Stress and Stresses data List you can specify the individual stress times in this area The list is edited by using the Insert Remove and Clear functions First Stress s the period of time that the first stress phase lasts Last Stress s the total time for the stress phase all the values in the stress list Stresses or Stresses Decade the points of the linear stress list or the points per decade of the log stress list Stress List lists all of the stress times see the next figure Figure 27 Stress measure sequence waveform Accumulated stress Accumulated stress Accumulated stress TO before stress Mme did time 55 0sec time 100 0sec Measure y y I I time Measure phase Stress monitor timing The Stress Monitor Timing is the measurement of current during the stress phase Each stress phase has stress monitor timing PLC power line cycle 0 001 25 Hold Time s when stress is enabled the voltage will hold the setting time before monitoring Sample Interval
29. 00 0 N pa uz z n suuz Dam ao aw ao par E sMu3 Gate 2 d 1 500 1 500 1 500 0 01 2 00 y N f sa Macias isuus Oran_2 a a ono ono cmo P o 01 OK Cancel 5 10 ACS2600RTM 900 01 Rev B December 2012 ACS 2600 RTM User s Manual Section 5 Voltage ram Breakdown settings When the Breakdown Settings function is selected a dialog box containing all of the breakdown criteria settings opens see next figure Figure 73 Breakdown settings for VRamp Be ae ci amara ve a move ono Fog o en 1x Pre lO Jie 00s y 100000 0 30 006 1 0 4 10 0 Ty 110 0 m 10 0 10 0 2 3e 006 1 0 fo I _fio 0 17 10 0 e hos o_ lie 005 Ey 1000 7 Init initial current for the VRamp that is used during the pre ramp and post ramp testing I Max I maximum current used during the stress ramp phase Critical critical current used during the stress ramp phase If the current exceeds this value more breakdown judgments Slope x Pre and x Pre will be performed Max Q maximum charge quantity used during the stress ramp phase Slope x Init checks the difference between the current and voltage to determine if the x times exceeds the initial slope l x Init checks to determine if the current exceeds x times of the initial current Slope x Pre checks to determine if the current versus voltage slope exceeds x times the previous slope x Pre checks to dete
30. 0e 001 L_______ 1 947820 010 2 619980 0142 000000 0049 000000e 001 1 ACS2600RTM 900 01 Rev B December 2012 1 11 Section 1 ACS 2600 RTM ACS 2600 RTM User s Manual e Status lists the test setting information in a text format Run a 2600 based RTM Manually run Select a node in the test tree then select the Start icon on the tool bar All of the selected tests under this node will be executed sequentially The test results data will be logged and saved as a csv file Automation 2600 based RTM tests run in Automation with control of the probe station for automated testing at the cassette level The settings are in the Automation panel refer to the ACS Reference Manual for more information document number ACS 901 01 The results of the test data is logged and saved as a csv file db file or kdf file 1 12 ACS2600RTM 900 01 Rev B December 2012 ACS 2600 RTM User s Manual Section 1 ACS 2600 RTM Preference settings Some settings for the Series 2600 and Series 2600B SourceMeters can affect the 2600 based RTM such as the running stability or speed To get to the Preferences settings do the following With ACS open go to Tools gt Preferences gt Misc In the Misc tab you can select the SMUs you need choose Auto Delay if needed and set the state for any unused SMUs see next figure Figure 11 2600 based RTM Preferences Check for selecting the SMU set to be 4 wire remote sense mode
31. 1 best fxed auto 3 SMU3 Source_1 best fxed auto 4 SMU4 Bulk_1 best fixed auto 3 4 ACS2600RTM 900 01 Rev B December 2012 ACS 2600 RTM User s Manual Section 3 Fast NBTI Figure 46 Timing Setting flow diagram e P A iP stress Drain 7 o Gate First Drain First Auto Post raw data In a sample test step if the points are set to more than one an average value of the measured current will be calculated and logged Post raw data will enable logging for all of the measured data rather than only the calculated average value post raw data must be selected to enable this function In order to reduce the recover time when the Drain First PLC lt 0 01 is selected the test flow overlaps the current measure around the specific test step and extracts the precise value from several measured data points Within all of the measured data the ones that are not in the measured region will be eliminated from the average calculation see next figure Enable the Post Raw Data function in order to log the data Figure 47 Multiple points sample test step diagram Gater WD a Gate TA i WHE Gate WHEE i f stress Eliminatod from average calculation vi Drai WM 1 Drain First Drain First Gate First PLC lt 0 01 PLC gt 0 01 ACS2600RTM 900 01 Rev B December 2012 3 5 Section 4 Time dependent dielectric breakdown In this section Testpinciples csi toco ide 4 1 instrument CONMECUON eicsioransn
32. 12 2 9 Section 2 HCl and NBTI ACS 2600 RTM User s Manual Output Parameter Settings In the Output Parameters Settings of the Pre Stress Tests tab the GUI is used to setup the exit criteria for the measured parameter or calculations from a formula see the next figure e Global select this option to set the parameter to a global variable which can be used in the other settings e Enable Exit select this option to enable the exit criteria based on the Exit Low and or the Exit High parameters e Exit Low the minimum value for the parameter If the device is below the minimum value the test for this device will end e Exit High the maximum value for the parameter If the device exceeds the limit the test for this device will end Figure 25 Output Parameters Settings exit criterai Exit criteria Stress settings The Stress Settings tab is used to setup the Stress Time Setting Stress Monitor Timing and the Stress Conditions see next figure Figure 26 Stress Settings GUI Pre Stress Tests Stress Settings Measure Post Stress Tests Stress Time Settings PLC 1 0 Lineal C Log C Lst First Stress s fico lege 0 0 Sample IntervaKs 0 5 Last Stress s 100 0 2 10 ACS2600RTM 900 01 Rev B December 2012 ACS 2600 RTM User s Manual Section 2 HCl and NBTI Stress time settings The Stress Time Settings GUI is used to setup the timing of stress measure sequence
33. 2 TestiW scada 5 4 SOMOS a ia aa ADA 5 6 General settings isione dd 5 7 Stress voltage compensation Sets i rare 5 7 High capacilanee Modernitas licita ile iaa llei dle ea eiai 5 9 Device ane MUSSO Susi ice 5 10 Breakdown Settings ereraa ies na dtcnsaniedias jalar ideal 5 11 Failure determi ria isa 5 11 A eseein a sce ccdac acc ae cucediaa a wadaacdacasaapecaed 5 12 OS 5 12 A E Arce a ee teat errr re 5 13 Ealtire Mode sao pia 5 13 Data ECON sisi iii alii 5 14 Ramped current 6 1 Testpincile ainda 6 1 INSTUMENT COMME CUOM rai id is idos 6 2 TES OW isis 6 4 SEMI A A A A L E E A A E 6 6 General Seti unio ies 6 7 Devices and SMU SOMIAGS 1 mii sii ias dida 6 8 e 5csmtcnes cousnsae peices sets vastatargiaes tea taeharceo hatte tanec car absence nein eras 6 8 Failure determinato a A DS 6 9 o O EE A 6 9 Rapita se 6 10 POSEA ao 6 10 Fall MOE scsi iii ita isaac E 6 10 ii ACS2600RTM 900 01 Rev B December 2012 ACS 2600 RTM User s Manual Table of Contents DAA WS CORI ducado 6 11 ElectromigratiOM ri a a de 7 1 TES PHARC lisa A A AAA AAA A 7 1 INSUUMENE COMMECUOM urna lid 7 2 TES Wise sides eiii 7 3 SO MINGS iia A E E A 7 6 A A etrrer rr crerre rrr ren 7 6 Gener SEUNG S sasssa aeee a E E aE eA E 7 7 Device and SMU SeHINGS s ccei sn cnt KR R RE 7 8 Exit CAMON Esaa e a e a EE 7 9 Data reCer Ai E 7 10 Poly Mesta iii 8 1 Testpincipl site 8 1 Instrument COMME CUOM AA AAA AS 8 1 TES Wir nata ana ii esa 8 3 A E Le O Peron O OE I E E E
34. 32755e 001 6 899959e 001 8 15376 1 63075 2 44613 ACS2600RTM 900 01 Rev B December 2012 ACS 2600 RTM User s Manual Section 1 ACS 2600 RTM Refresh function updates the displayed data or plot Export Data function logs data and saves the file to the following location on your hard drive ACS Projects lt project name gt Realtime_Data Realtime_Data_ lt date and time gt csv In addition for the 2600 based RTM tests ACS logs the data of the test running to a temporary file in the following location ACS Projects lt project name gt RTM_temp curdata_ lt date and time gt tmp The temporary file is used to log data in case the current test that is running stops inadvertently ACS also provides a tool to read the temporary file that will convert it to a db or csv file The tool can be accessed in the tool bar by going to Tools and select the Read Current Test Data in the drop down menu Figure 16 Show Current Test Data Lot Id Wafer Id Ske 1d step Ste Coord Pattern pattern 1 Test Type Test Name HCI Group oro p2 Test input Attribute sub_device num attribute name list attribute value list 1 fw L V Gate _1 V_Draln_1 V_Source Li 0 059999999999999998 1 5 3 0 0 2 2 W L V_Gate_2 V_Drain_2 V_Source_2 2 0 0 059999999999999998 0 0 0 0 A gt Test Output Var var name var value NN PS Save To 08 Save To csv Read Other Ext Data
35. 900000e 00 x 011 6 412740e 01 12 000000e 001 1 000000e 001 1 5949008 0017 5108708 0012 534080e 009 1 827830e 001 1 800000e 00 6 3588608 011 9 473980 0112 000000e 00 2 0000008 001 1 083080e 0042 746530e 009 1 844050e 001 1 700000e 00 s se3o30e 011 1 188630e 01d2 000000e 00 3 000000e 001 1 2 3 4 5 6 3 9811008 0011 4492708 0042 949240e 009 1 868450e 001 1 600000e 00 1 066700e 010 1 387060e 0142 000000e 00 4 000000e 001 7 16 3096008 0011 1 251510e 010 1 586680e 01 2 000000e 0045 000000e 001 8 9 10 11 ma tem tem tan f 1 000000e 0042 4 1 442120 010 1 747490e 0102 000000e 009 6 000000e 003 1 584890e 0023 1 566270e 010 1 937390e 0142 000000e 0047 000000e 001 2 511890e 0024 1 763880e 010 2 208800e 01 1 947820e 010 2 619980e 014 2 000000e 00 ce y gt Tro Teo Too Tro 3 gt gt S o 2 2 gt S S o gt 6 ACS2600RTM 900 01 Rev B December 2012 1 17 Section 1 ACS 2600 RTM ACS 2600 RTM User s Manual Automation data security Event Security service or possible options Real time data save RTM_temp curdata_ lt date and time gt tmp Note kdf csv db file are not updated in real time but updated at test end or site end Thus they cannot be an alternate option to secure data and prevent user from data loss by abort operation or unexpected tester behavior Progress monitor
36. CHING takes less time for one test step and is able to bias an inter stress level between test steps The measurement induced recover time will lead to less shift The NBTI_FAST_SWITCHING is similar to the test flow of the HCI NBTI test refer to the previous section for more information Figure 41 Voltage and time shift curve Apparent exponent 101 103 10 107 109 Time sec Section 3 Fast NBTI ACS 2600 RTM User s Manual Sequential versus parallel For multiple sub devices NBTI_FAST_SWITCHING can be set to sequential or parallel Parallel testing will establish its own test flow for each sub device while sequential testing will setup one test flow for all of the sub devices The NBTI_FAST_SWITCHING sequential test works in serial mode which means that after testing one sub device is complete then the next sub device is tested This is different from HCI NBTI VRamp JRamp and TDDB_CVS tests The reason is that timing control is extremely strict for NBTI_FAST_SWITCHING Therefore it is recommended that you use parallel testing for multiple sub devices if you are concerned about the amount of timed needed to complete all of the testing Measure phase timing The NBTI_FAST_SWITCHING test has three stages 1 Pre Stress measurement 2 Stress Measure sequence 3 Post Stress measurement The timing diagram in the next figure shows these stages The pre stress post stress and stress phase of the stress measure sequence are
37. Check All to check all the SMUs utomatically inserts a current range dependent delay when measuring current Af preferring measuring accuracy turn it on If preferring measuring speed turn it off etting the unused SMU state Default apply 0V not flow more than 1mA High Impedance disconnect the output relay Force Current 0A app ACS2600RTM 900 01 Rev B December 2012 1 13 Section 1 ACS 2600 RTM ACS 2600 RTM User s Manual You must choose the preference settings for the RTM or ITM instruments before running a test If you change the preferences the settings will be effective at the beginning of the next execution of the RTM or ITM test Also you should use the Initialize Unused SMU option when you need to isolate the devices This option enables you to control multiple isolated devices If you are accomplishing multiple device probing it s possible that some of the probed devices have broken due to the trial test or for other reasons The broken devices can affect other devices depending on the issue For example with leakage noise or inducing breakdown through an electrical short The Series 2600 and Series 2600B SourceMeters have output relays and several off modes which can benefit you if you need to test multiple devices Some 2600 based RTMs have the ability to isolate the break down in devices during a test sequence See the details in each section describing the RTM tests Data logging When
38. _DRAIN the drain current measured in the test V_GATE the gate voltage forced in the test START_l the start current to define the calculation region STOP _l the stop current to define the calculation region Figure 34 SS parameters Logl10 Id Returned Value Logl0 I_START _ d logli0 Id d Vg Logl0 I_ STOP Vg Example SO SS I Drain 1 V Gate 1 1 3e 5 1 5e 5 2 18 ACS2600RTM 900 01 Rev B December 2012 ACS 2600 RTM User s Manual Section 2 HCl and NBTI SSVTCI Purpose extract the sub threshold swing for a certain duration between the left offset and right offset of the constant current threshold voltage Format SSVTCI 1 DRAIN V_GATE VTCI LEFT OFFSET RIGHT OFFSET _DRAIN the drain current measured in the test V_GATE the gate voltage VTCI constant current threshold voltage LEFT OFFSET RIGHT_OFFSET left offset and right offset of the constant current threshold voltage Figure 35 SSVTI parameters SN LEFT OFFSET Log10 Id Returned Value _ q logl0 Id 7 d Vg ur GHT_OFFSET VTCI vg Example SLOPE SSVTCI I Drain 1 V Gate 1 VTH 0 1 0 1 TAR_IATV Purpose For two data arrays and V in order to find the target _ tar corresponding to V_tar and V are two one to one correspondent data arrays Format TAR _IATV V_DRAIN 1 DRAIN V tar Figure 36 TAR_IATV parameters Id Return valuek
39. _EM test based on the JESD61A 01 standard The difference is that the Poly_Heater uses a different poly material as a heater for the DUT device under test while the Iso _EM uses the metallization to self heat This is due to low resistance of the metallization line and it needs a relatively high current to self heat to a high temperature Also the Poly_Heater test uses the Series 2600A or Series 2600 SourceMeters for sourcing and measuring Instrument connection One Poly_Heater device has two parts 1 Heater forces current on Heat Hi terminal forces OV on Heat Lo terminal 2 Metal line DUT two terminal or four terminal Two terminal forces current and measures voltage on Force Hi forces OV on Force Lo Four terminal forces current on Force Hi forces OV on Force Lo forces OA on Sense Hi and Sense Lo measures voltage at Sense Hi Figure 95 Poly Heater device type Sense Hi Sense Lo Force Hi pur ForceLo Force Hi ForceLo Two terminal DUT Four terminal DUT Section 8 Poly heater ACS 2600 RTM User s Manual The test uses Series 2600B or Series 2600 SourceMeters The SourceMeters can be setup as different groups GPIB or Ethernet for parallel testing Within each group you can also setup multiple sub devices for sequential or parallel testing In a parallel test each sub device will be set as a sub group DTNS Group The SourceMeters in a connection scheme must have the same firmware The 2600B SourceM
40. _test Ramping Post_test je gt lt A Force Vuse Force linit lt Meas Meas V Force linit Optional Meas V a 0 If you select Ibound the current will ramp to a constant value and is held at this value for the duration of the test The waveform is shown in the next figure Figure 80 Stress waveform of Ibound Pre_test Ramping Post_test k rie Ibound Force Vuse Force linit Meas Optional Force linit Meas V Meas V gt ACS2600RTM 900 01 Rev B December 2012 Section 6 Ramped current ACS 2600 RTM User s Manual Settings The JRamp TDDB_CCS test characterizes the gate oxide reliability property for a MOSFET Note that the test drain source and bulk are all set to ground GND Thus the device can be extracted as a capacitor When you select multiple sub device modules in the device level of the test tree the tddb_parallel and tddb_shared_sub in CUSTOM are appropriate for the JRamp TDDB_CCS test The JRamp TDDB_CCS GUI for testing in shown in the next figure Figure 81 GUI for the JRamp TDDB_CCS 0000 pie fio Low angela fies eee ee o e ae veal io E mm Ny EZ Men E a SS an Wy Y SC jeooo Joo fy low fo fos 2 MI fieoofio fos fy fon ho WJ lori 6 6 ACS2600RTM 900 01 Rev B December 2012 ACS 2600 RTM User s Manual Section 6 Ramped current General settings Max Time s the maximum time for the current ra
41. a Road Cleveland Ohio 44139 440 248 0400 Fax 440 248 6168 1 888 KEITHLEY www keithley com 12 06
42. am log lg Average and Log Average and Log Stress time Logged data time Ig _O Discard data ACS2600RTM 900 01 Rev B December 2012 4 9 Section 4 Time dependent dielectric breakdown ACS 2600 RTM User s Manual Dynamic limit setting The Dynamic Limits Change allows the limit values for the gate SMU to vary The next figure is an example of a Dynamic Limits Change with a varying limit Figure 58 Diagram of Dynamic Limit change Igate Current Limit Dynamic Limit Change is enabled _ Break Down Time Time The Series 2600B and Series 2600 SourceMeters can set the current limits when applying the voltage The output current will be clamped to the set limit to prevent damage to the DUT The Dynamic Limit setting enables the dynamic limit change feature When enabled the limit value will vary according to the settings The limit value can be set as a multiple of the measured current If the current changes smoothly the limit will not be reached However if the current changes suddenly which indicates a breakdown the output will be clamped to the limit value and protect the DUT from severe damage Figure 59 Dynamic Limit settings Dynamic Limit M Enable Lowest Limit A 1e 008 Trigger Rate 10 0 Limit Percent 100 0 Lowest Limit A if the gate current is lower than this value the Dynamic Limit will not be applied Trigger Rate if the gate current changes the Trigger Ra
43. analysis Most of the 2600 based RTM tests are in accelerated conditions which are higher than normal working conditions for example exceeding normal stress conditions The data results will provide statistical analysis regarding prediction time for a device to degrade or breakdown e The ACS software Statistics function is able to import a kdf file for various statistical analysis The detailed description is in the ACS Reference manual document nubmer ACS 901 01 e Keithley Instruments Inc provides a separate tool for statistical analysis that is named KDAT For more information contact your local Keithley office ACS2600RTM 900 01 Rev B December 2012 1 19 Section 2 HCI and NBTI In this section a em Cerecer E 2 1 instrument CONMECUON sci scisesescasecacidataesentaxensatoesasameassantaaseriaian 2 3 RS SU OW ees a eae 2 4 O 2 6 Global VnablES sicion aa a aa aa aaiae 2 15 Formula E 2 16 Data recording esisi e E E 2 23 Test principle Hot carrier injection HCI is a process where high lateral electrical fields in a MOSFET generate hot carriers high energy electrons or holes that can damage the MOS gate oxide interface and degrade the device s current and voltage l V characteristics The threshold voltage of the MOSFET will change over time due to HCI The HCI test measures the change of the MOSFET parameters when the device is under a voltage stress Negative bias temperature instability NBTI experienced b
44. and post test for pass or fail The pre test and post test are always in the flow while this option is used to indicate whether to check the results linit in the optional pre test used to determine if the measured current luse exceeds the linit In the pre test and post test the force linit is used to determine if the measured voltage Vpre and Vpost are lower than Vuse Vuse forced value in the optional pre test and the voltage judgment used the pre test and post test multV determines if the voltage is lower than the multV times the previous multV The value is 0 1 0 Ibound select if needed for a bounded JRamp test For a bounded JRamp test the current will ramp from the Istart to the bound and hold on the Ibound until the breakdown or max time is reached The maximum time of the stress phase is the minor one of Istart to Imax time and Max Time Max Q determines if the maximum charge quantity is larger than this value Lowest V determines if the voltage is lower than this value Failure determination The results from a test failure are shown in the next figure Figure 85 Fail test results for JRamp TDDB_CCS Ig Regular oxide IV Pre post test linit Optional pre test Initial test In the optional pre test a voltage Vuse is applied to the gate If the measured current Tuse is larger than Tinit the device is considered to have failed the initial test In the pre test a current Iinit is app
45. arallel and tddb_shared_sub in CUSTOM are appropriate for a VRamp The VRamp GUI for testing is shown in the next figure Figure 68 GUI for VRamp T zN l lll _ 1e 00 fl _ 100000 0 My fseoos 1 2 del lueoos fe 100000 0 fe f3e006 1 ACS2600RTM 900 01 Rev B December 2012 ACS 2600 RTM User s Manual Section 5 Voltage ramp General settings Max Time s the maximum time for the voltage ramp When the max time is reached the ramp test will stop and the device is considered to have passed PLC number of power line cycles This parameter is constant and cannot be changed Low Range A the lowest current measure range that is used during auto ranging Monitor at Vuse if selected the current is monitored when the Vuse voltage is applied see next figure Output Vbox at Ibox When selected Vbox will be one of the output parameters Tbox is an optional measured current level for which the stress voltage is recorded while Vbox is the applied voltage at the step where the oxide current exceeds Tbox JESD35 A The output voltage is the first ramp voltage that causes the current to exceed Ibox Real time post data e When deselected the test module will post all the data after the entire ramp test is done e When selected the time to post and data point to post options are enabled The test data will be post and be sent from the instruments to ACS after every Time to post time interval or after the specifi
46. arias ir eana OESE 4 2 TESTO o Meta 4 3 A ating E A E I E nang ieds 4 5 Failure Aeterna sascveas scakcdassacesoonsdnactakesienbapadatasakeacssanntan s 4 14 Data recorte 4 15 Test principle The time dependent dielectric breakdown TDDB test is intended to estimate the acceleration parameters needed to predict the wear out time of a MOSFET gate oxide This describes the TDDB test under constant voltage stress CVS The TDDB_CVS test is normally run for long time several hours to several days The stress voltage is higher than the working voltage of a MOSFET and is used to accelerate the breakdown The test result is statistically analyzed to predict the normal wear out time The next figure shows a typical TDDB_CVS test result for a MOSFET Note that the a illustration is of a measured gate current versus the stress time and b is a gate current vs time and noise vs time Figure 48 Typical TDDB_CVS test result TDOB Constant Voltage Stress 102 3 A E 1te 5 1teb te 7 lt 1e 8 1e 9 variance of delta I 5 1e 10 h tet E 32 10 12 Ps SE 10 13 baseline 500X increase 4 E ieis Ei e15 S 1e16 1017 sample size 5 ies A E pr 1e 20 Areas x 10 em 1e 21 Break Down Time Time 0 500 1000 1500 2000 Time s a b The TDDB_CVS test has three stages optional pre test stress stage main loop of the stress measure sequence and on optional post test The pre test is used to verify the functional
47. at Inter Stress A stress stress lt sweep sample NBTI_FAST_SWITCHING f Y Yj stress stress HCUNBTI ov Measure phase ACS2600RTM 900 01 Rev B December 2012 3 3 Section 3 Fast NBTI ACS 2600 RTM User s Manual e During the measure phase HCI NBTI will lower the bias to O volts and then execute the test steps The NBTI_FAST_SWITCHING test will directly go to the test step from the stress voltage level e After one test step is completed the HCI NBTI will lower the bias to 0 volts before the next test step The NBTI_FAST_SWITCHING will bias at the inter stress phase and then go to the next test step The intermediate time is called inter delay The inter stress level is set in the stress conditions Sample test step timing setting A sample test step is a test step that has a fixed bias compared to sweep It is used to reduce the measurement time The NBTI_FAST_SWITCHING test has a timing control for the sample test in the measure phase test step In the next figure the Common Setting is used to select a timing mode for all of the sample test steps in measure phase Figure 45 Test Settings and Timing Setting Name Points V_Gate_1 V_Drain_1 V_Source_1 V_Bulk_1 I_Gate_1 I_Drain_1 I_Source_1 1_Bulk_1 Formula Timing 1 measo 51 0 2 1 5 lo 0 O Y O O vic es Timing cell Timing Setting meast FS Test Specified Settings SMU Pad Name 5ource Rang Meas Range MSD Gate_1 best fxed auto 2 SMU2 Drain_
48. breakdown Fail_mode_ lt sn gt Fail mode lt sn gt the number of the sub device lt pad gt pad name usually the gate in JRamp TDDB_CCS For example sub device 1 pad name Gate_1 the measured voltage in ramp steps is V_Gate_1_moni_1 ACS2600RTM 900 01 Rev B December 2012 6 11 Section 7 Electromigration In this section Testpinciple ice 7 1 instrument Connection sci scisvsessassracidataesensaxensatoesasameasseantansovianans 7 2 VES o ia tetas 7 3 O cats aand nese 7 6 ENE e lo chin ccs ized 7 9 Data record isis 7 10 Test principle Electromigration is the phenomenon of material movement resulting from electrical current and is a major reliability concern for metallization The isothermal electromigration test Iso_EM is an accelerated electromigration test performed on microelectronic metallizations In the isothermal test an attempt is made to maintain a constant mean temperature of the line under test This is done by varying the stress current and therefore the amount of Joule heating imparted to the line based on the JESD61A 01 standard The Iso_EM test uses the Series 2600A or Series 2600 SourceMeters for sourcing and measuring The Iso_EM test uses an isolated thermal algorithm to heat the metallization to a constant temperature and hold this temperature until the metallization fails The test result is used to predict the metallization wear out time Figure 86 Diagram of Iso_EM test results 1200
49. cess the test is performed by forcing a current and measuring the resultant heat current The DUT is defined as the source current and R_dut is measured This is when the temperature temperature is calculated using the TCR temperature coefficient of resistance and power are calculated The only difference between the Poly Heater test from Iso_EM test is the way to determine the heat current value of the next step A Determination of R_poly and R_dut at chuck temperature In this part a small current linit is forced through the poly heater in both polarities and R_poly is measured and averaged And Isource is forced through the DUT and R_dut is measured and averaged If the R_dut value exceeds the given criterion Rchuck_fail the test will end B Initialization phase R_poly Tchuck 50 is estimated by TCR and the exit criterion in this phase is calculated from this R_poly value with an input shift This phase begins when the first heat current in this phase is applied The heat current forced increases by a factor fcurrent This phase ends when the temperature exceeds Tchuck 50 and after at least five steps If the R_dut value exceeds given criterion the test will end C Temperature staircase and convergence phase This phase is composed of two sub phases Temperature staircase and Convergence The R_dut value at Ttest is estimated and exit criterion is determined by R_dut Ttest and a shift value e Temperature staircase In this part
50. e Szress Tests Stress Settings Measure Post Stress Tests Formula formula editing area Formula List the existing formulas Variables lists all of the variables that can be used in the formula Theses variables are forced and selected in the test step Constants area for editing constant variables which can be used in a formula Attributes the attributes of a device usually the W and L The W and L can be used as a variable in a formula They are set in the Device level in the Test tree for a single device or on the Stress Settings tab for multiple sub devices Parameter Extraction Functions lists all the available formula functions In the Formula List Variables Constants Attributes or Parameter Extraction Functions area double clicking any item will add that string to the Formula area for editing As in the previous figure the VT_1 VTLINGM _Drain_1 V_Gate_1 is edited using the formula output name VT_1 and using the variables I_Drain_1 and V_Gate_1 Select Add to add this formula to the Formula List Select OK to complete this action and VT_1 will be displayed in the formula cell And VT_1 will be added into the Output parameter settings exit criteria and VT_1 will be automatically added a postfix _pre1 from the test step name ACS2600RTM 900 01 Rev B December 2012 ACS 2600 RTM User s Manual Section 2 HCl and NBTI Parameter extraction functions This area lists all the a
51. e for every sample interval using the following two equations Stress voltage compensation equations The following settings see next figure are the necessary parameters for the voltage compensation Figure 60 Stress Voltage Compensation settings Stress Voltage Compensation V Enable voltage Gap v 0 01 Break Count 10 Protect R ohm 1000 0 ACS2600RTM 900 01 Rev B December 2012 4 11 Section 4 Time dependent dielectric breakdown ACS 2600 RTM User s Manual Enable Enable the stress voltage compensation function Check the box to enable the stress voltage compensation function Voltage Gap V Allowed maximum voltage difference between Vtarget and Vdut used to determine the compensation loop Break Count Maximum count of the voltage compensation loop Protect R ohm Resistance for the protection resistor dRact When the stress voltage compensation is enabled the actual voltage on a device Vdut will be posted in the Data tab The column name is V_dut_ lt sn gt sn is the number of the device The following two equations are used Vcomp Vtarget Idut dRact e Vcomp is the voltage force at loop n 1 e Vtarget is the desired stress voltage target on the device under test DUT e Idut is the measured current at loop n e dRact is the resistance of the protection resistor Vdut Vcomp Idut dRact e Vdut is the actual voltage stress on the DUT e Vcomp is the force voltage at loop n e idut i
52. ed number of points based on the data points to point setting These settings are critical wnen the VRamp module is used in a large scale ramp test If multiple instruments are used in one Group for example up to eight Model 2636As in one Group with an extended ramp test this option is safe for data logging and transferring Figure 69 Real time post data diagram logtig Hih t0 ti t2 Stress time Stress voltage compensation setting In some cases for instance when testing high power devices a protection resistor is inserted in series with the SMU in order to prevent the rush current at break down point and prevent oscillation The inserted protection resistor will cause a voltage drop which means the SMU forcing voltage should be compensated in order to maintain a constant voltage stress on the device To get the desired stress voltage on the device the SMU forcing voltage should make a compensation to achieve the proper value The voltage compensation has two phases e Initial speed up loop at the start of the stress e Voltage compensation during the stress ACS2600RTM 900 01 Rev B December 2012 5 7 Section 5 Voltage ramp ACS 2600 RTM User s Manual Initial speed up loop At the start of the stress an initial speed up loop is used to get the voltage on the device under test Vdut close to the desired stress voltage Vtarget If the absolute value of Vdut Vtarget is greater than the Voltage Gap us
53. en group 2 must also have three Model 2636As The device settings will automatically apply to all the selected groups If you want to add a 2600 based RTM test to run in parallel ACS will automatically create DTNS groups according to the configuration of the sub devices and pad settings Each sub device will be set as one DTNS group if the sub device has been set to a pad To run parallel testing each pad must have only one sub device NOTE If you have the Series 2600B or Series 2600 instruments that have two SMUs it is highly recommended that the two SMUs are set to the same sub device If you assign the two SMUs to different sub devices the instrument configuration will contain two separate DTNS group numbers and the two sub devices will run sequentially as opposed to running in parallel Figure 8 DTNS group run in sequence Sequential Sequential Sequential prrr isc lia PAN smua_smub smua_smub smua_smub Ssposs eee mere ys a E Subordinate Node 3 TSP LINK Parallel running among DTNS Group Add a new RTM Click the RTM icon to add a new 2600 based RTM test In the dialog box that opens select the type of test that is needed and select Sequential or Parallel The Sequential and Parallel options are for a GPIB or Ethernet group If you select Parallel it will create a DTNS group based on the sub devices Figure 9 Add a RTM test E Test Setup Patterns gt gia
54. ent compliance unit are amps Target Temp C target stress temperature lexit A if the calculated next heat current to be forced exceeds this value the test will end Rehuck ohm when the initial R Chuck temperature exceeds this value the test will end Rshift Phase1 when the measured R exceeds the calculated Rcal Tchuck 50 x 1 Rshift the test will end Rshift Phase2 when the measured R exceeds the calculated Rcal Target temperature x 1 Rshift the test will end Rshift_warn Phase3 when the measured R exceeds the calculated Rtestx 1 Rshift_warn a warning will be given and the time will be logged as Twarn Rshift Phase3 when the measured R exceeds Rtestx 1 Rshift the test will end Real is the calculated resistance at the target temperature the calculation is made using the measured R and the TCR Rtest is the resistance when entering phase 3 and corresponds to the temperature Ttest Figure 102 Device and SMU settings for Poly Heater Dev Area Pin Target exit Rehuck Rshift Rshift Rshift_warn Rshift Checked Mo om2 SMU Terminal o Compl omp oc A ohm Phasel Phase2 Phase3 Phase3 350 0 1 250 0 2 0 2 0 02 0 1 350 0 1 250 0 2 0 2 0 02 0 1 ACS2600RTM 900 01 Rev B December 2012 8 9 Section 8 Poly heater ACS 2600 RTM User s Manual Exit criteria When the measured or calculated result exceeds the exit criteria the test will end and the fail time will be lo
55. er specified then the loop will continue if it is less than the Voltage Gap the loop will end Voltage compensation The voltage compensation during the stress will calculate the next force voltage for every sample interval using the following two equations Stress voltage compensation equations The following settings see next figure are the necessary parameters for the voltage compensation Figure 70 Stress Voltage Compensation settings Stress Yoltage Compensation IV Enable voltage Gap fo o1 Break Count fio Protect R ohm 1000 0 Enable Enable the stress voltage compensation function Check the box to enable the stress voltage compensation function Voltage Gap V Allowed maximum voltage difference between Vtarget and Vdut used to determine the compensation loop Break Count Maximum count of the voltage compensation loop Protect R ohm Resistance for the protection resistor dRact When the stress voltage compensation is enabled the actual voltage on a device Vdut will be posted in the Data tab The column name is V_dut_ lt sn gt sn is the number of the device The following two equations are used Vcomp Vtarget Idut dRact e Vcomp is the voltage force at loop n 1 e Vtarget is the desired stress voltage target on the device under test DUT e Idut is the measured current at loop n e dRact is the resistance of the protection resistor Vdut Vcomp Idut dRact Vdut is the actua
56. erature and Constant will force a constant current Material Select Al or Cu Each has a different temperature calculation refer to the JESD61A 01 standard TCR Ref Temp 0C temperature coefficient of resistance at the reference temperature Ref Temp 0C reference temperature Chuck Temp OC chuck temperature Jchuck A cm2 chuck heat current density used to measure R at the chuck temperature Ichuck is calculated by Jchuck and the area The area is set in the device and SMU settings The value should be small enough to avoid unwanted heating Jstart A cm2 the heat current density that is used to start the Poly_Heater test The Istart is calculated using Jstart and the area The area is set in the device and SMU settings Current Multi Phase1 next heat current will be the previous current multiplying this value The _next _prex Current Multi in Phase 1 This value should be larger than 1 the recommended range of values is 1 1 1 5 Istart and Current Multi control phase 1 The temperature range in phase 1 is from Tchuck to about Tchuck 500C and at least five steps are taken These two parameters should be choosen to ensure that the temperature increases to neither too fast nor too slow Temp Step Phase2 C temperature step value used in the staircase section in phase 2 This recommended range of values for this parameter is 8 10 C The temprature will increase linearly using the Temp Step
57. erion Rchuck_fail the test will end Initialization phase R Tchuck 50 is estimated by the TCR and the exit criterion in this phase is calculated from this R value and an input shift The test begins when the first current in this phase is applied The current forced increases by a factor fcurrent This phase ends when the temperature exceeds Tchuck 50 and after at least five steps If the R value exceeds the given criterion the test will end Temperature staircase and convergence phase This phase is composed of two sub phases Temperature staircase and Convergence The R value at Ttest is estimated and the exit criterion is determined by R Ttest and a shift value e Temperature staircase In this part the current is calculated from the relationship of T R and T P and increased so that the temperature will increase almost linearly by AT This part ends when the temperature achieves Ttest 2xAT e Convergence In this part the current is calculated from the relationship of T R and T P and forced so that the temperature will converge to Ttest quickly and smoothly Stress phase In this phase the temperature is kept constant by keeping power constant from the relationship of T P The R value obtained at the beginning of this phase and a shift value determines the exit criterion Post fail measurement After the device fails the R will be measured again using the same current for R Tchuck An example test results diagram is shown
58. ert Global function and the Insert global variable dialog box opens You can select the variable that is needed by double clicking it for example that VT_1_pre1 When you double click the variable it will open another dialog box In this box you can edit the expression for example VT_1_pre1 0 5 This expression will be used as the input Also the global expression can be used as a value for the sweep for example in a cell as 0 VT_1_ pre ACS2600RTM 900 01 Rev B December 2012 Section 2 HCl and NBTI ACS 2600 RTM User s Manual Formulator 2 16 In Pre Stress Tests Measure and Post Stress Tests a formula can be added to a test step As in the next figure click the Formulator function or double click the formula cell and a dialog box opens see the next figure the Formulator Settings to add or edit formula to the selected test step The formula is used to extract a device parameter from the measured data The parameter calculated using the formula can be logged for analysis and set as an input value in the following test steps The formula is real time which means the formula will be calculated once the current test step is completed The extracted parameter will be logged and tracked for later use The formula settings are much like the Formulator in Data tab Though the available formula functions are less the functions include most of the parameter extractions of the MOSFET Figure 32 Formulator Settings Pr
59. es to limit fault current and voltage to the card Before operating an instrument ensure that the line cord is connected to a properly grounded power receptacle Inspect the connecting cables test leads and jumpers for possible wear cracks or breaks before each use When installing equipment where access to the main power cord is restricted such as rack mounting a separate main input power disconnect device must be provided in close proximity to the equipment and within easy reach of the operator For maximum safety do not touch the product test cables or any other instruments while power is applied to the circuit under test ALWAYS remove power from the entire test system and discharge any capacitors before connecting or disconnecting cables or jumpers installing or removing switching cards or making internal changes such as installing or removing jumpers Do not touch any object that could provide a current path to the common side of the circuit under test or power line earth ground Always make measurements with dry hands while standing on a dry insulated surface capable of withstanding the voltage being measured The instrument and accessories must be used in accordance with its specifications and operating instructions or the safety of the equipment may be impaired Do not exceed the maximum signal levels of the instruments and accessories as defined in the specifications and operating information and as shown on the instrume
60. ess Phase3 the stress phase continues until the resistor fails or reaches the maximum time ACS2600RTM 900 01 Rev B December 2012 8 5 Section 8 Poly heater ACS 2600 RTM User s Manual Settings For a single sub device the Poly_Heater test can use the PolyHeater 2Wire or PolyHeater 4Wire device type in the Custom category for multiple sub devices the test can use a 24pin_6PolyHeater device type in the Custom category The GUI for the Poly_Heater is shown in the next figure Figure 99 GUI for Poly Heater checked a EE comet eG ain ame Po ha 8 6 ACS2600RTM 900 01 Rev B December 2012 ACS 2600 RTM User s Manual Section 8 Poly heater Timing settings Max Time maximum test time in seconds Max Count largest number of data measurements Once a test reaches either the Max Time or Max Count the data measurements will end Step Delay measurement cycle in seconds recommended in 0 05 0 5 Log Interval data record interval in Phase 3 in seconds Low Range the lowest current measure range that will be used during auto ranging Figure 100 Timing settings GUI for Poly Heater M Timing i Max Time 5000 0 Max Count 100000 Step Delay fo Log Interval fo Low Range A fie ACS2600RTM 900 01 Rev B December 2012 8 7 Section 8 Poly heater ACS 2600 RTM User s Manual General settings Test Mode In the stress phase phase 3 the Constant P T will force constant power to reach constant temp
61. etermine what triggers an end to device testing an absolute value or a percentage of a value Exit Target absolute value shift from the reference value or a percentage shift from the reference value The reference value is the parameter measured or calculated in the first measure phase For example in the previous figure the VT_MEAS1_meas0 parameter is set to Absolute and the Exit Target is 0 2 If the difference absolute value between VT_MEAS1_meas0 in the current measure phase and TO measure phase is more than 0 2V the test for the device will exit Post Stress Tests The Post Stress Tests tab is used to setup the post stress stage The GUI is similar to the Pre Stress Tests Refer to Pre Stress Tests for more a more detailed description The only difference is that there is no exit criteria setting for parameters on the Post Stress Tests tab ACS2600RTM 900 01 Rev B December 2012 2 13 Section 2 HCI and NBTI 2 14 ACS 2600 RTM User s Manual Preference settings If you want to configure and enable the tests for running the HCI NBTI that affect the test performance you will have to open Preferences in the Tools drop down menu and go to the Misc tab see next figure Figure 29 Preferences settings for HCI_NBTI v v V SMU3 v SMU4 Check for selecting the SMU set to be 4 wire remote v sense mode Y SMU6 Check All to check all the SMUs Y SMU7 ecommend to set re
62. eters and the 2600 SourceMeters for instance the A and non A versions cannot be used together A typical connection scheme is shown in the next figure Figure 96 A typical instrument connection scheme 3 225 KEITHLEY GPIB Cables Or TSP LINK Subordinate Node3 Subordinate Node3 eee eee eee ee eeeeeeeeeeet dnog SNLO Guowe Bujuuns Peed Subordinate Node4 dno19 SNLG Guowe Bujuuny eed sss 0 Shen 2 AA ets su a g 1 Group 2 el J Parallel running among GPIB or Ethemet Group 8 2 ACS2600RTM 900 01 Rev B December 2012 ACS 2600 RTM User s Manual Section 8 Poly heater Test flow The Poly_Heater test flow is based on the JEDEC standard JESD61A 01 see next figure Figure 97 Test flow of Poly Heater Poly Heater DUT Iheat Iheat_pre f gt Tchuck 50 amp Step gt 5 Cale Rth_poly TO Meas R_dut time T Meas R_poly Cale P Meas R_dut a Tchuck ACS2600RTM 900 01 Rev B December 2012 8 3 Section 8 Poly heater ACS 2600 RTM User s Manual The test contains five parts 1 Determination of R_poly and R_dut at chuck temperature 2 Initialization phase 3 Temperature staircase and convergence phase 4 Stress phase 5 Post fail measurement The temperature is increased during the 2nd and the 3rd part of the test and is kept constant during the 4th part The detailed algorithm could be found in the JEDEC standard document During he entire pro
63. eters and the 2600 SourceMeters for instance the A and non A versions cannot be used together A typical connection scheme is shown in the next figure Figure 77 A typical instrument connection scheme GPIB Cables Or TSP LINK Subordinate Node3 Subordinate Node3 EETETTETTETELTELELITELEELEI dnog SNLG Buowe Hujuurnu eed Subordinate Node 4 dnog SNLG Buowe Hujuuni 9 pe1e d Group 1 Group 2 e _ oo oe Parallel running among GPIB or Ethemet Group 6 2 ACS2600RTM 900 01 Rev B December 2012 ACS 2600 RTM User s Manual Section 6 Ramped current Due to limited memory space and communication speed of the instruments the ramp rate and stress interval settings will be affected by how the instruments are arranged A connection scheme with more instruments will need more time to accomplish a stress interval The next table lists the stress interval settings for some typical instrument configurations The smallest recommended settings are shown for each configuration Instrument configuration Mode Stress interval Max time 1x16 Sequential 1 57600 Parallel 0 07 3600 0 5 4000 2x8 Sequential 0 07 10800 Parallel 0 3 10000 Sequential 0 2 10000 4x4 Parallel 1 57600 0 07 10000 8x2 Sequential 0 1 10000 1 57600 Parallel 0 1 10000 Instrument configuration n x m represents a connection scheme o
64. f n Groups every group has m nodes For example in Figure 1 the instrument configuration is 2 x 4 ACS2600RTM 900 01 Rev B December 2012 Mode means the execution mode of the JRamp TDDB_CCS test It is selected when the test is added refer to Figure 1 6 3 Section 6 Ramped current ACS 2600 RTM User s Manual Test flow The JRamp TDDB_CCS test flow is based on the JESD35 A standard The JRamp TDDB_CCS parameters are also defined by the JESD35 A standard The JRamp TDDB_CCS test flow is shown 6 4 in the next figure Main loop Optional Pre test Force Vuse measure luse Pre test Force linit measure Vpre Stress stage Figure 78 JRamp_TDDB_CCS test flow ompliance luse gt linit2 Pre test Initial test fail ompliance Stop test Begin Current Ramp Istress Istart Breakdown judgment lt U N Ramp test fail Ramp test fail Ramp test fail Ramp test pass Stop stress stage N ontinue stress stage Next ramp step ACS2600RTM 900 01 Rev B December 2012 ACS 2600 RTM User s Manual Section 6 Ramped current The pre test optional pre test forces Vuse to measure luse the pre test forces linit and measures Vpre The post test force linit and measure Vpost The stress phase main loop of the JRamp TDDB_CCS test the stress waveform is shown in the next figure Figure 79 JRamp_TDDB stress waveform Pre
65. face see the next figure Figure 3 SMU designation in ACS GROUP 1 Local name Cente tees cee eeneeeeee me SMU1 SMU3 smu2 SMU4 NOTE Only the Series 2600B Series 2600 and Model 4200 SMU has a local name Due to a single GPIB address or IP address these instruments are able to form a multiple instruments network The Series 2600B and Series 2600 use TSP Link while the Model 4200 can have several SMU cards ACS2600RTM 900 01 Rev B December 2012 1 5 Section 1 ACS 2600 RTM ACS 2600 RTM User s Manual Sequential and parallel All of the 2600 based RTMs can be run sequentially or in parallel The parallel operation will be achieved using the following two methods 1 ACS will recognize all of the GPIB groups or Ethernet groups to run in parallel Each group will execute the same test flow when the group is selected on the device setting interface see next figure 2 Within the GPIB group or Ethernet group the TSP Link network of instruments can be set to a DTNS dynamic TSP Link network subdivision group or groups for parallel running The DTNS group sub networks is also recognized as a sub group in ACS Each sub group is connected to one sub device see next figure Figure 4 Sequential or parallel connection scheme GPIB Cables Or Ethernet Cables with hub or router Master Node 1 Master Node 1 posepose ad a2 e a a gt p260000 00 Ed a ao 9
66. following table Parameter Unit Comment Time_ lt sn gt S Time stamps Temperature_ lt sn gt Calculated temperature R_ lt sn gt Ohm Calculated resistance _ lt sn gt A Measured current Power_ lt sn gt WwW Calculated power TCR_Tchuck_ lt sn gt K TCR value at chuck temperature Rinit_Tchuck_ lt sn gt Ohm Resistance at chuck temperature Rtest_ lt sn gt Ohm Resistance when phase 3 begins Ptest_ lt sn gt Ohm Power when phase 3 begins Jtest_ lt sn gt Alem Current density when phase 3 begins t_P3begin_ lt sn gt S Time when phase 3 begins Twarn_ lt sn gt S The time when resistance reaches the warning value time is recorded from the start of t_P3begin TTF_ lt sn gt S Failure time from t_P3begin Failtime_ lt sn gt S Failure time from test beginning Rend_Tchuck_ lt sn gt Ohm Resistance at chuck temperature after test failmode_ lt sn gt Fail mode lt sn gt the number of the sub device Section 8 Poly heater In this section OSU PGI GION acs icons 8 1 instrument CONMECUON sci scisvsccsacscaciaasaussndaserectonsasiensaxseacteasareaiins 8 1 TES it ea 8 3 PUN ca E E A T T 8 6 REE E EE dl lo EEA 8 10 Data record snina a e E RS 8 11 Test principle Electromigration is the phenomenon of material movement resulting from electrical current and is a major reliability concern for metallization The Poly_Heater test procedure and algorithm is similar to the Iso
67. form Accumulated stress Accumulated stress Accumulated stress time 10 0sec time 55 0sec TO before stress time 100 0sec Measure time Measure phase Twait s When coming to a measure phase the software will wait Twait seconds before any measurement SILC Vuse_1 or Vuse_2 Test Config clicking this button will pop up a window allowing the user to select whether to operate the optional test steps Pre Post test SILC test Vuse_1 Vuse_2 Breakdown settings Current Limits the breakdown settings used during current monitoring If these fields are selected they will be used to evaluate the device under test e Jmax the maximum current density The current density is calculated by Igate WxL The W and L are gate width and length which is set in the test tree device for a single sub device or SMU settings multiple sub devices If the monitor current density exceeds this value the device has failed by definition e J JO the current density change ratio compared to the first value If the monitor current density change ratio exceeds this value the device has failed by definition e qmax the maximum accumulated charge density The accumulated charge density is calculated by the accumulated gate charge divided by the gate area If it exceeds this value the device has failed by definition e J Jpre current density change ratio compared to the previous value If monitor current density change ratio exceeds this
68. gged The following defines the exit criteria 8 10 Resistance criteria in each phase either the absolute value or the shift Refer to the Rchuck Rshift Phase1 Rshift Phase2 and Rshift Phase3 settings Maximum source current Refer to the lexit setting Voltage compliance Refer to the Compl setting Maximum time Refer to the Max Time setting Maximum count of data Refer to the Max Count setting The next table lists the failure modes of the Poly_Heater which will be logged as a test fail Failure mode 1 Comments Calculation error Reach maximum time or maximum count of data Resistance fail Initialization phase fail Reach voltage compliance BAjoOo n 0 Reach maximum source content ACS2600RTM 900 01 Rev B December 2012 ACS 2600 RTM User s Manual Section 8 Poly heater Data recording The test results data are displayed on the Data tab and will be logged as a kdf db or csv file if run in the Automation mode Data for multiple Groups are displayed using multiple tabs within the Data tab The output data for different sub devices is distinguished by the parameter names The output parameters for one group are in the following table Parameter Unit Comment Time_ lt sn gt S Time stamps Temperature_ lt sn gt Calculated temperature R_poly_ lt sn gt Ohm Calculated poly heater resistance R_dut_ lt
69. gt qmax Maximum charge density Soft breakdown judgment calculate the noise of Imoni to see whether exceeds the limit change ratio Optional Post test Force Vpost measure Ipost ACS2600RTM 900 01 Rev B December 2012 ACS 2600 RTM User s Manual Section 4 Time dependent dielectric breakdown Pre test optional pre test force Vpre and measure Ipre Post test optional post test force Vpost and measure Ipost Vpre and Vpost are equal Stress measure sequence main loop of TDDB_CVS test The waveform of TDDB_CVS test is shown in the next figure note that the pre post tests SILC V_USE1 V_USE2 measure phase tests are optional Figure 51 Waveform of TDDB_CVS test Hold Time Sample interval Pd X V_USE2 Optional V_USE1 Optional V_SILC Optional m f t f t t_meas0 t_meas1 t_meas2 measn Pre Test Post Test Optional lt _ Stress Measure Sequence gt Optional Settings The Definition tab GUI of the TDDB_CVS settings are shown in the next figure Figure 52 GUI for the TDDB_CVS ACS2600RTM 900 01 Rev B December 2012 4 5 Section 4 Time dependent dielectric breakdown ACS 2600 RTM User s Manual Stress measure time sequence settings PLC number of power line cycles 0 001 25 Min Time s the starting measure phase time Max Time s the ending measure phase time Low Range A the lowest current measure range that will be used duri
70. gure 66 VRamp test flow Pre test force Vpre Measure Ipre Initial test fail Stop test Initial test fail Stop test Stress stage Main loop Begin Votage Ramp Vstress Vstart Force Vstress or Vuse in Monitor time ompliance s Measure Imoni under Vstress or Vuse reakdown judgmen Stop stress stage Stress voltage Vstress Veatress Vstep Continue stress stage Next ramp step Y Post test force Vpost Post test fail 5 4 ACS2600RTM 900 01 Rev B December 2012 ACS 2600 RTM User s Manual Section 5 Voltage ramp The pre ramp test forces the Vpre and measures the Ipre The post ramp test forces Vpost and measures Ipost The stress phase the main loop of the VRamp test two waveform types see next figure Figure 67 Stress waveform _use_pre Ramping _use_post E Mode 1 5 Monitor Current is e measured under First ramp Ramp rate 2 the current ramped point e voltage level Stress Mode 2 Interval Se Monitor Current is gt measured under Vuse ACS2600RTM 900 01 Rev B December 2012 Section 5 Voltage ramp ACS 2600 RTM User s Manual Settings 5 6 The VRamp test characterizes the gate oxide reliability property for a MOSFET and in the test drain the source and bulk are set to ground GND Thus the device can be extracted as a capacitor When you select multiple sub devices at the device level in the test tree the tddb_p
71. her is a data array it will return the product arrays every data of the array multiples the single data VSUB Purpose return the results of V1 minus V2 Format VSUB V1 V2 Remark If V1 and V2 are all single data it will return the results of V1 minus V2 If V1 and V2 are all data arrays with the same length it will return the arrays subtraction results one to one result If one is a single data and the other is a data array it will return the array subtraction results every data of the array is correspondent to the single data ACS2600RTM 900 01 Rev B December 2012 ACS 2600 RTM User s Manual Section 2 HCl and NBTI VTCI Purpose calculate the constant current threshold voltage as defined by VTCI VGS ID UxW L The W and L are the gate width and gate length The U is an empirical drain current per square of the channel refer to JEDEC standard JESD28 A JESD60A Format VICI U W L 1 DRAIN V_ GATE Figure 37 VTCI parameters Id Return value vd VTCI_LOG10 Purpose calculate the constant current threshold voltage as defined by VTCI VGS ID UxW L The W and L are the gate width and gate length The U is the drain current per square of the channel refer to JEDEC standard JESD28 A JESD60A The VTCI is obtained by log10 Id versus Vdrain Format VTCI_LOG10 U W L I_DRAIN V_GATE Figure 38 VTCI_LOG10 parameters log10 Id logl0 UXW L L Return value vd ACS2600RTM 900
72. ided by the product warranty may be impaired The types of product users are Responsible body is the individual or group responsible for the use and maintenance of equipment for ensuring that the equipment is operated within its specifications and operating limits and for ensuring that operators are adequately trained Operators use the product for its intended function They must be trained in electrical safety procedures and proper use of the instrument They must be protected from electric shock and contact with hazardous live circuits Maintenance personnel perform routine procedures on the product to keep it operating properly for example setting the line voltage or replacing consumable materials Maintenance procedures are described in the user documentation The procedures explicitly state if the operator may perform them Otherwise they should be performed only by service personnel Service personnel are trained to work on live circuits perform safe installations and repair products Only properly trained service personnel may perform installation and service procedures Keithley Instruments products are designed for use with electrical signals that are rated Measurement Category and Measurement Category II as described in the International Electrotechnical Commission IEC Standard IEC 60664 Most measurement control and data I O signals are Measurement Category and must not be directly connected to mains voltage or to voltage
73. igh Impedance in Initialize unused SMU ACS2600RTM 900 01 Rev B December 2012 4 3 Section 4 Time dependent dielectric breakdown ACS 2600 RTM User s Manual 4 4 Figure 50 Test flow of TDDB_CVS Optional Pre test Force V pre measure Ipre Jpre gt Jmax pre post or Jpre lt Jmin prefpost The first Measure phase SILC test get Isilc Force Vuse_1 measure luse_1 Force Vuse_2 measure luse_2 Stress measure sequence Main loop lt Stress phase breakdown Stress phase end Measure phase SILC test get Isilc Force Vuse_1 measure luse_1 Force Vuse_2 measure luse_2 SILC Breakdown tress measure sequence end Initial test fail Stop test ote J is current density calculated by I W L is measured current W and L is the dimensions of MOSFET 1 SILC test SILC is stress induced leakage current Force Vsile measure Isilc Sweep Vsilc measure current Isic is the measured current at Vcheck 2 SILC Breakdown judgment Jsilc gt Jmax Maximum current density Jsilc JO gt JJO Current density change ratio compared to the first value Jsilc Jpre gt J Jpre Current density change ratio compared to previous value 3 Stress phase breakdown judgment Jmoni gt Jmax Maximum current density Jmoni JO gt J J0 Current density change ratio compared to the first value Jmoni Jpre gt J Jpre Current density change ratio compared to previous value qmoni
74. ilure modes are categorized in the next table Failure type Initial test Ramp test Post test Initial type 1 Fail N A N A Catastrophic type 2 Pass Fail Fail Masked Catastrophic type 3 Pass Pass Fail Non catastrophic type 4 Pass Fail Pass Monitor fail type 5 N A Fail N A All pass type 6 Pass Pass Pass 6 10 ACS2600RTM 900 01 Rev B December 2012 ACS 2600 RTM User s Manual Section 6 Ramped current Data recording The test results data are displayed on the Data tab and will be logged as a kdf db or csv file if run in the Automation mode Data for multiple Groups are displayed using multiple tabs within the Data tab The output data for different sub devices is distinguished by the parameter names The output parameters for one group are in the following table Parameter Unit Comment Time_ lt sn gt S Time stamps _ lt pad gt _pre_ lt sn gt A Measured current in optional Pre ramp test V_ lt pad gt _prer_ lt sn gt V Measured voltage in Pre ramp test _ lt pad gt _moni_ lt sn gt A Force current value in ramp step V_ lt pad gt _moni_ lt sn gt V Measured voltage in ramp step Q_ lt pad gt _moni_ lt sn gt C Accumulated gate charge V_ lt pad gt _post_ lt sn gt V Measured voltage in Post ramp test Tbd_ lt sn gt S Breakdown time Vbd_ lt sn gt V Breakdown voltage lbd_ lt sn gt A Breakdown current Qbd_ lt sn gt C Quantity of charge when
75. in seconds recommended in 0 05 0 5 Log Interval data record interval in Phase 3 in seconds Low Range the lowest current measure range that will be used during auto ranging Figure 92 Timing settings GUI CS aio EE El 7 6 ACS2600RTM 900 01 Rev B December 2012 ACS 2600 RTM User s Manual Section 7 Electromigration Generl settings Test Mode In the stress phase phase 3 the Constant P T will force constant power to reach a constant temperature and Constant will force a constant current Material Select Al or Cu Each has a different temperature calculation refer to the JESD61A 01 standard TCR Ref Temp 0C temperature coefficient of resistance at the reference temperature Ref Temp 0C reference temperature Chuck Temp OC chuck temperature Jchuck A cm2 chuck current density used to measure R at the chuck temperature Ichuck is calculated using Jchuck and the area The area is set in the device and SMU settings The value should be small enough to avoiding unwanted heating Jstart A cm2 the current density that is used to start the Iso_Em test The Istart is calculated using Jstart and the area The area is set in the device and SMU settings Current Multi Phase1 next current will be the previous current multiplying this value The _next _prex Current Multi in Phase 1 This value should be larger than 1 the recommended range of values is 1 1 1 5 Istart and Current Mu
76. in the next figure ACS2600RTM 900 01 Rev B December 2012 ACS 2600 RTM User s Manual Section 7 Electromigration Figure 90 Result diagram of Iso_EM 500 A initialization a temperature staircase convergence stress T_ 450 C T 200 C chuck 10 t s Phase 1 Phase 2 Phase 3 Initialization Phase1 this phase begins at Tchuck and ends at about Tchuck 50 0C Temperature staircase Phase2 part 1 the temperature increases linearly to a certain temperature step until about Ttest 2xstep Convergence Phase2 part 2 the temperature converges to Ttest rapidly and smoothly Stress Phase 3 the stress phase continues until the resistor fails or reaches the maximum time ACS2600RTM 900 01 Rev B December 2012 7 5 Section 7 Electromigration ACS 2600 RTM User s Manual Settings For a single sub device the Iso_EM test can use the Resistor_2T or Resistor_4T device type for multiple sub devices the test can use the 24pin_6R device type in the Custom category The GUI for the Iso_EM is shown in the next figure Figure 91 GUI for Iso_EM Device and SMU Settings conte E om cone Ey esl o U l U SMU y U i y Timing settings Max Time maximum test time in seconds Max Count largest number of data measurements Once a test reaches either the Max Time or Max Count the data measurements will end Step Delay measurement cycle
77. ity of the device the stress stage is used to apply a constant voltage stress to the device until breakdown and the post test is used to characterize the device after the stress stage Section 4 Time dependent dielectric breakdown ACS 2600 RTM User s Manual Instrument connection The TDDB_CVS test applies a stress voltage to a MOSFET gate and set GND ground to bulk source and drain The test uses the Series 2600A or Series 2600 SourceMeters Multiple SourceMeters can be setup as a connection scheme for multiple devices in a configuration of different groups GPIB or Ethernet Group for a parallel test Within each group you can also setup multiple sub devices for sequential or parallel run In parallel run each sub device will be set as a sub group DTNS group Note that the SourceMeters in a group connection scheme must have the same firmware The 2600B SourceMeters and the 2600 SourceMeters for instance the A and non A versions cannot be used together A typical connection scheme is shown in the next figure A typical connection scheme that shows two GPIB or Ethernet Groups Group 1 and Group 2 is shown in the next figure Each Group has four instruments Node 1 master and Node 2 is set to a DTNS group 1 sub group 1 Node 3 and 4 are set to DTNS group 2 sub group 2 Figure 49 A typical instrument connection scheme GPIB Cables Or DTNS Group 1 v e v z TSP a gt ob LINK 7 Subordinate Node2
78. l voltage stress on the DUT e Vcomp is the force voltage at loop n e Idut is the measured current at loop n e dRact is the resistance of the protection resistor 5 8 ACS2600RTM 900 01 Rev B December 2012 ACS 2600 RTM User s Manual Section 5 Voltage ramp High capacitance mode In some cases the device under test DUT has high capacitance for example in a high power device therefore the SMU should be set to high capacitance mode for better measurement When high capacitance mode is enabled a minimum load capacitance of 100 nF is recommended In absence of this minimum load capacitance overshoot and ringing may occur In order to enable high capacitance select the Enable High Capacitance mode option see the next figure Also the SMU low range and current compliance value must be greater than or equal to 1e 6 For more details about the Series 2600B instrument high capacitance mode refer to the Series 2600B Reference manual Figure 71 Enabled high capacitance mode IV Enable High Capacitance mode ACS2600RTM 900 01 Rev B December 2012 5 9 Section 5 Voltage ramp ACS 2600 RTM User s Manual Device and SMU settings The device and SMU settings are all set at the device level For example all of the devices and SMuUs that are assigned in the device level of the test tree such as the Group No Dev No SMU and Terminal are shown in the next figure W um L um determine the MOSFET device dimensions Dev Type
79. lied to the gate If the sourcing SMU is in compliance or the measured voltage Vpre is lower than Vuse the device is considered to have failed the initial test If the device is considered to have failed the initial test the test for the device will terminate ACS2600RTM 900 01 Rev B December 2012 6 9 Section 6 Ramped current ACS 2600 RTM User s Manual Ramp test In a ramp step a current Istress is applied to the gate and voltage Vmoni is measured Compliance check if the sourcing SMU is in compliance the device is considered to have failed the ramp test Voltage factor if the measured Vmoni is lower than the previous ramp step voltage times the multV the device is considered to have failed the ramp test Lowest voltage if the measured Vmoni is lower than lowest V the device is considered to have failed the ramp test Maximum charge if the calculated Qmoni is larger than the Omax the device is considered to have failed the ramp test The accumulated charge Qmoni is calculated according to stress current and stress interval Post ramp test When the ramp test is completed or exits due to breakdown a post ramp test is performed by applying a gate current Tinit and measuring the voltage as Vpost If the sourcing SMU is in compliance or Vpost is lower than Vuse the device is considered to have failed the post test Failure mode According to the pass or fail criteria for the Initial Ramp and Post tests the fa
80. lly before performing the indicated procedure The CAUTION heading in the user documentation explains hazards that could damage the instrument Such damage may invalidate the warranty Instrumentation and accessories shall not be connected to humans Before performing any maintenance disconnect the line cord and all test cables To maintain protection from electric shock and fire replacement components in mains circuits including the power transformer test leads and input jacks must be purchased from Keithley Instruments Standard fuses with applicable national safety approvals may be used if the rating and type are the same Other components that are not safety related may be purchased from other suppliers as long as they are equivalent to the original component note that selected parts should be purchased only through Keithley Instruments to maintain accuracy and functionality of the product If you are unsure about the applicability of a replacement component call a Keithley Instruments office for information To clean an instrument use a damp cloth or mild water based cleaner Clean the exterior of the instrument only Do not apply cleaner directly to the instrument or allow liquids to enter or spill on the instrument Products that consist of a circuit board with no case or chassis e g a data acquisition board for installation into a computer should never require cleaning if handled according to instructions If the board become
81. lti control phase 1 The temperature range in phase 1 is from Tchuck to about Tchuck 500C and at least five steps are taken These two parameters should be chosen to ensure that the temperature increase is neither too fast nor too slow Temp Step Phase2 C temperature step value used in the staircase section in phase 2 The recommended range of values for this parameter is 8 10 C The temprature will increase linearly using the Temp Step Conver Factor used in the Convergence section in phase 2 The recommended range of values for this parameter is 1 3 Error Band C if the temperature is within the target temperature for instance target temperature Error Band then phase 2 ends and phase 3 begins Figure 93 General Settings GUI General Settings Test Mode Constant P T Constant I Material al y TcR Ref Temp oc 0 0033 Ref Temp C 26 0 Chuck Temp C 26 0 Jchuck A cm2 0 001 Jstart A cm2 0 001 Current Multi Phase1 fi Temp Step Phase2 C 10 0 Conver Factor 2 0 Error Band C 1 0 ACS2600RTM 900 01 Rev B December 2012 7 7 Section 7 Electromigration ACS 2600 RTM User s Manual Device and SMU settings The device and SMU settings are all set at the device level For example all of the devices and SMUs that are assigned in the device level of the test tree such as the Group No Dev No SMU and Terminal are shown in the next figure Area cm2 the cross section area
82. m of the monitor current noise and the baseline noise is based on the JEDEC standard JESD92 Measure phase breakdown Stress induced leakage current SILC is measured during the measure phase to determine a breakdown in the device Maximum current density Jmax if the SILC current density exceeds Jmax the device has failed by definition and jumps to the post test Current density ratio J JO if the SILC current density changes ratio is larger than the setting value as compared to the first value JO the device has failed by definition Current density ratio J Jpre if the SILC current density change ratio is larger than the setting value as compared to the previous value Jpre the device has failed by definition 4 14 ACS2600RTM 900 01 Rev B December 2012 ACS 2600 RTM User s Manual Section 4 Time dependent dielectric breakdown Post test The Post test applies a gate bias voltage Vpost and measures the gate current Ipost If the calculated gate current density exceeds the high limit Jmax or the low limit Jmin the the device has failed the post test by definition Failure mode According to the pass or fail conditions for the Initial BD breakdown and Post tests the failure modes are categorized as shown in the next table Failure type Initial test BDtest Post test Initial type 1 Fail N A N A Catastrophic type 2 Pass Fail Fail Masked Catastrophic type 3 Pass Pas
83. mit Jmin the device has failed the initial test by definition and testing will end In multiple device tests the testing for the failed device will end while the others will continue to be tested Stress measure sequence During the stress phase the monitor current Imoni will be used to determine if a breakdown occurs during testing In the measure phase the SILC test current Isilc will be used to determine if a breakdown occurs If a breakdown occurs the test flow for the device will exit the stress measure sequence and jump to the post test and the device has failed by definition a BD breakdown has occurred Stress phase breakdown Maximum current density Jmax if the current density exceeds the Jmax the device has failed by definition and jumps to the post test Current density ratio J JO if the current density changes ratio is larger than the setting value compared to the first value in JO the device has failed by definition Current density ratio J Jpre if the current density change ratio is larger than the setting value compared to the previous value Jpre the device has failed by definition Maximum charge density qmax if the charge density exceeds qmax the the device has failed by definition Soft breakdown limit calculates the noise of Imoni to see if it exceeds the limit change ratio If the noise setting value is larger than the baseline noise the device has failed by definition The calculation algorith
84. mote sense mode v SMU8 Automatically inserts a current range dependent delay when measuring current f preferring measuring accuracy turn it on If preferring measuring speed turn it off Setting the unused SMU state Default apply OV not flow more than 1mA High Impedance disconnect the output relay Force Current OA apply OA ACS2600RTM 900 01 Rev B December 2012 ACS 2600 RTM User s Manual Section 2 HCl and NBTI Global variables In the pre stress and post stress stages a measured or calculated parameter can be set as a global variable These global varibales can be used as input values in the pre stress test steps measure phase and post stress For example in the Pre Stress Tests settings select the Global option to make it a global variable see next figure Figure 30 The Global variable Check for global variable Output Parameters Settings 1 0 1e 005 1 Drain_1_pre0 I_Drain_1 0 0 001 3 VT_1_prel VT_1 0 5 1 4 Once a global variable has been set it can be used as input see next figure Figure 31 Insert a global variable Tests Settings Name Points V_Gate_1 V_Drain_1 V_Source_1 V_Bulk_1 I_Gate_1 I_Drain_1 1_Source_1 I_Bulk_1 Formula Timing 1 meas 11 0 2 1 5 0 0 m m O DO VT_MEAS1 2 measi 3 I_Gate_1 pred vT_1_pre1 05 If you want to edit the V_Gate_1 cell right click the cell and you will see the Insert Global function Click the Ins
85. mp time When the max time is reached the ramp test will stop and the device is considered to have passed PLC number of power line cycles Low Range A the lowest current measure range that is used in auto ranging Data Compression log compressed data according to the settings This function can reduce the total amount of data without losing track of the parameter changes Time Linear or Log only one option can be selected Linear For the Constant time measured one data is logged The data is the mean value of the period Log Every decade a Points per decade number of data is logged The data is the measured value at the time point Vgate Shift if the measured data shifted the Shift Rate it will be logged Start s at the beginning of a ramp after the data compression time setting as been applied Figure 82 JRamp TDDB_CCS data compression diagram Vgate ox OO ry AP A Average and Lo Average and Log 9 s Stress time Logged data time Vgate O Discard data ACS2600RTM 900 01 Rev B December 2012 6 7 Section 6 Ramped current ACS 2600 RTM User s Manual Device and SMU settings The device and SMU settings are all set at the device level For example all of the devices and SMuUs that are assigned in the device level of the test tree such as the Group No Dev No SMU and Terminal are shown in the next figure W um L um determine the MOSFET device dimensions Stress Setting
86. nd each group has two DTNS groups The two groups will run tests in parallel and the two DTNS groups also run in parallel NOTE The following 2600 based RTMs have a different sequential timing diagram HCI NBTI TDDB_CVS VRamp JRamp TDDB_CCS These 2600 based RTMs will incur the source stress simultaneously and they will measure the affect sequentially Note that the NBTI_FAST_SWITCHING test runs in sequential mode which means it tests a sub device until it is finished and then it will test the next sub device Figure 5 Sequential timing diagram Measure phase stress stress sub device 1 sub device 2 sub device 3 ACS2600RTM 900 01 Rev B December 2012 1 7 Section 1 ACS 2600 RTM ACS 2600 RTM User s Manual ACS 2600 based RTM general settings The ACS 2600 based RTM tests can be added to the test tree The RTM is at the test modules level in the test tree which is the same level as the ITM PTM STM and CTM Add a new device ACS software contains basic types of semiconductor devices Additionally there is a CUSTOM category that includes several multiple pin device types These devices enable test and measurement of several components when a probe is connected to a probe card All of the components are designated as sub devices in ACS and all of the components together are called the device which is part of the test tree The next figure is an example of how to add a device that contains two NMOSFETs as two s
87. ng auto ranging Monitor monitor time settings Monitor is defined as current measurements during the stress phase e Sample Interval s the time interval between two monitor points e Hold Time s During the stress phase this is the amount of time the stress voltage will be applied before the monitor measurement is made Time Array the measure phase stress intervals The first measure phase time is the Min Time excluding the very first measure phase before stress phase and the last measure phase time is the Max Time e Linear the measure phase times are a linear distribution with an equally spaced number of points set by the Points field e Log the measure phase times are a log distribution and every decade has Points Decade number of values e List the measure phase times are a customized list of values Figure 53 Stress measure time sequence settings Min Time s 10 PLC 11 0 Max Time s 100 0 Low Range A 1e 8 m Monitor 7 Sample Interval s 1 0 Hold Time s 0 5 Test Config Diagram Copy 1st to All 4 6 ACS2600RTM 900 01 Rev B December 2012 ACS 2600 RTM User s Manual Section 4 Time dependent dielectric breakdown For the Time Array shown in Figure 6 10 55 100 the stress measure sequence voltage waveform is illustrated in Figure 7 TO measure is the very first measure phase before any stress Figure 54 Stress measure sequence wave
88. nt or test fixture panels or switching card When fuses are used in a product replace with the same type and rating for continued protection against fire hazard Chassis connections must only be used as shield connections for measuring circuits NOT as protective earth safety ground connections If you are using a test fixture keep the lid closed while power is applied to the device under test Safe operation requires the use of a lid interlock Ifa screw is present connect it to protective earth safety ground using the wire recommended in the user documentation The A symbol on an instrument means caution risk of danger The user should refer to the operating instructions located in the user documentation in all cases where the symbol is marked on the instrument The A symbol on an instrument means caution risk of electric shock Use standard safety precautions to avoid personal contact with these voltages The A symbol on an instrument shows that the surface may be hot Avoid personal contact to prevent burns The 7 symbol indicates a connection terminal to the equipment frame If this symbol is on a product it indicates that mercury is present in the display lamp Please note that the lamp must be properly disposed of according to federal state and local laws The WARNING heading in the user documentation explains dangers that might result in personal injury or death Always read the associated information very carefu
89. of the metallization used to calculate the current from the current density setting Compl compliance limit value For the Force Hi Sense Hi and Sense Lo terminals it is the voltage compliance units are volts for the Force Lo terminal it is the current compliance units are amps Target Temp C target stress temperature lexit A if the calculated next current to be forced exceeds this value the test will end Rchuck ohm when the initial R Chuck temperature exceeds this value the test will end Rshift Phase1 when the measured R exceeds the calculated Rcal Tchuck 50 x 1 Rshift the test will end Rshift Phase2 when the measured R exceeds Rcal Target temperature x 1 Rshift the test will end Rshift_warn Phase3 when the measured R exceeds Rtestx 1 Rshift_warn a warning will be given and the time will be logged as Twarn Rshift Phase3 when the measured R exceeds Rtestx 1 Rshift the test will end Real is the calculated resistance at the target temperature the calculation is made using the measured R and the TCR Rtest is the resistance when entering phase 3 and corresponds to the temperature Ttest Figure 94 Device and SMU settings for Iso_EM Dev Area Pin Target exit Rechuck Rshift Rshift Rshift_warn Rshift Checked No cm2 SMU Terminal No Compl romp 0c A ohm Phasel Phase2 Phase3 Phase3 350 0 1 250 350 0 1 250 7 8 ACS2600RTM 900 01 Rev B
90. ojects lt project name gt data lt test_module_name gt csv The data results are displayed in the data tab and plot is available The data and plot in the data tab will update over a certain period of time However since some ACS 2600 based RTM tests are long term tests frequently updating data is not necessary Although if desired ACS provides an option to manually update the data and plot In the file ACS KATS ACS_setting ini setting auto_update_manual_run_plot 0 enables manually updating the data and plot The data and plot will update only you select the Refresh function However note that if the refresh updates a large amount of data it will take a while to be displayed Figure 14 Manually update and plot data Plot and Data C Plot Only C Data Only Resort outputs Click to refresh the data and plot ORIGINAL DATA vglD Si VgID Linear t 10 25 t 0 20 j015 0 10 2 EE Source 13 i 0 05 2 1 i 1 i y nr 1 1 i i 1 i i 100 1 2 0 1 5 1 0 W5 6HIRTS 10 15 O 05 10 15 20 25 30 35 40 00 05 10 15 20 25 30 35 40 y 1 1 ws L 34 Eire vas 2 0 30 33 50 25 A 3 020 TS TE de O OR CI Y Time str Time str 1 rib RETHLEY D Y1 E F 6 Ha 1 3100 0 000000e 004 1 191580e 004 1 985450e 009 1 782010e 009 2 000000e 00 2 875330e 01 42 000000e 0011 0 000000 00d 1 000000e 0014 6145208 0012 6166408 009 1 836590e 001 1
91. oup 1 Group 2 e _ e oe Parallel running among GPIB or Ethemet Group 5 2 ACS2600RTM 900 01 Rev B December 2012 ACS 2600 RTM User s Manual Section 5 Voltage ramp Due to limited memory space and communication speed of the instruments the ramp rate and stress interval settings will be affected by how the instruments are arranged A connection scheme with more instruments will need more time to accomplish a stress interval The next table lists the stress interval settings for some typical instrument configurations The smallest recommended settings are shown for each configuration Instrument configuration Mode Ramp rate V s at Interval 1x16 Sequential 0 2 1 Parallel 0 2 1 2 2x8 Sequential 0 2 0 3 Parallel 0 2 0 3 4x4 Sequential 0 2 0 2 Parallel 0 2 0 3 16x1 Sequential 0 2 0 5 1 Instrument configuration n x m represents a connection scheme of n Groups every group has m nodes For example in the next figure the instrument configuration is 2 x 4 Mode means the execution mode of the VRamp module It is selected when the test module is added refer to the next figure ACS2600RTM 900 01 Rev B December 2012 5 3 Section 5 Voltage ram ACS 2600 RTM User s Manual Test flow The VRamp test flow is based on the JESD35 A standard The VRamp parameters are also defined by the JESD35 A standard The VRampl test flow is shown in the next figure Fi
92. pMOSFET are meaningful For multiple devices in the CUSTOM option the following device types for the HCI NBTI are available 20term_dev 24pin_6dev 25pin_8dev 25term_dev nmos_2 device Some of the device types have common terminals that is they have a common gate You can add an HCI NBTI test under the specified device The GUI for the HCI NBTI test is as shown in the next figure The GUI settings consist of four tabs Pre Stress Tests Stress Settings Measure Post Stress Tests Figure 21 GUI settings for HCI_NBTI test Definition Data Status Pre Stress Tests Stress Settings Measure Post Stress Tests F our tabs settings for test flow stages Comments Stress Time r S Settings 1 0 C Linear C Log C List Hold r First Stress s 10 0 eo Sample Intervaks 1 0 Last Stress s 100 0 Low Range A ies E real rears fea Test Sequence Dagram J je 2 2 ACS2600RTM 900 01 Rev B December 2012 ACS 2600 RTM User s Manual Section 2 HCl and NBTI Pre Stress Tests settings The Pre Stress Tests tab is where you setup test steps in the pre stress stage In this stage all of the test steps are executed sequentially There are five functions at the bottom of the GUI and there are two functions on the right side Add adds one test step at a time Delete deletes one test step at a time Formulator edits the formula of the selected test step Timing edits the timing of
93. provided that the current is set to ramp up to a specified level and then is held until breakdown The TDDB_CCS time dependent dielectric breakdown test under constant current stress uses constant current as stress to the oxide which can be achieved by setting it as a bounded JRamp or by setting the multiplier between the two stress currents to one The JRamp TDDB_CCS module test flow has three phases pre test stress phase post test The pre test is used to verify that the functionality of the device and stress phase are used to apply a ramped current waveform to the device until it breaks down and the post test is used to characterize the device after the ramp Figure 76 Diagram of JRamp_TDDB_CCS test results Qbd evaluation Vgate Break Down Time Time or Break Down Charge Charge Section 6 Ramped current ACS 2600 RTM User s Manual Instrument connection For a MOSFET device under test DUT the JRamp TDDB_CCS applies a stress current to the gate and bulk and the source and drain are connected to to ground GND The test module uses the Series 2600A or Series 2600 SourceMeters Multiple SourceMeters can be setup as a connection scheme for multiple devices in a configuration of different groups GPIB or Ethernet Group for parallel testing Within each group you can also setup multiple sub devices for sequential or parallel tests In a parallel test each sub device will be set as a sub group DTNS Group The 2600B SourceM
94. reakdown type fail mode Qbd_ lt sn gt C Quantity of charge when breakdown lbd_ lt sn gt A Breakdown current _gate_last_ lt sn gt A The last measured gate current before breakdown lt sn gt the number of the sub device lt pad gt pad name usually the gate in TDDB_CVS For example sub device 1 pad name Gate_1 the measured pre test current is Gate_1_pre_1 ACS2600RTM 900 01 Rev B December 2012 Section 5 Voltage ramp In this section TesturnnciplOs ticos osos 5 1 instrument CONMECUON ieiosi nansnaa ire ria 5 2 PESO ais 5 4 A cada N EE I E 5 6 Failure GetSrmiMatOn ssascveasscaicdaisaceseoasdnactakeaienbapadatasabeacnsannians 5 11 Data recordihgise lic 5 14 Test principle The voltage ramp VRamp test uses a ramped voltage stress on the capacitors or gate oxides to characterize the defects of dielectrics at lower electrical fields The stressed voltage starts at a lower level and ramps linearly until the oxide breakdown occurs VRamp tests are often applied to oxides where characterization of the defects at lower electric fields is important JESD35 A The VRamp test uses the Series 2600A or Series 2600 SourceMeters for sourcing and measuring The VRamp test has three stages Pre test stress stage and post test Pre test is used to verify the functionality of the device the stress stage is used to apply the ramped voltage stress to the device until breakdown and the post test is used to characterize
95. rithms for all of the 2600 based RTMs are based on but not limited to JEDEC standards ACS2600RTM 900 01 Rev B December 2012 ACS 2600 RTM User s Manual Instrument connection scheme Section 1 ACS 2600 RTM The Series 2600B and Series 2600 can be connected to a computer controller through a GPIB or Ethernet connection On each GPIB address or Ethernet IP address a group of instruments can be connected in series through the TSP Link as Node 1 Node 2 Node 3 etc NOTE It is highly recommended that one tester uses instruments of the same model for instance Model 2636A Also all of the instrument s firmware must be the same version Typical connection scheme Single GPIB or Ethernet group with one or more instruments The instruments are connected using TSP Link in a daisy chain configuration Figure 1 typical connection scheme 3 225 one Cable ACS2600RTM 900 01 Rev B December 2012 3 220 Ethernet KENHLEY ITHLEY Cable e te Section 1 ACS 2600 RTM ACS 2600 RTM User s Manual Multiple GPIB or Ethernet connection scheme for example groups with several instruments The instruments are connected in groups using TSP Link in a daisy chain configuration Figure 2 GPIB or Ethernet connection scheme 3a gt 2 KEITHLEY lt gt aa s eecjocce AS Subordinate esececes gt IE lt gt aa Subordinate seeeccccce gt Priston 2
96. rmine if the current exceeds x times the previous current Slope x Init and x Init are not available in the VRamp test module Failure determination The results from a test failure are shown in the next figure Figure 74 Fail test results Current Max I Hard Break Down S slope ratio o or C urrent ratio Critical I Ibox Vbox vbd Voltage ACS2600RTM 900 01 Rev B December 2012 5 11 5 12 Section 5 Voltage ramp ACS 2600 RTM User s Manual Initial test The VRamp test begins by performing a pre ramp test The pre ramp test applies a gate bias voltage Vpre and measures the gate current as Ipre If Tpre exceeds the current limit the device is considered to have failed the initial test and the test will terminate In the case of multiple device tests the test flow for the failed device will end however testing will continue for the other devices Ramp test The current measurements for one ramp step are Istress and Imoni Istress is measured at the ramp voltage level Imoni is measured at either the ramp voltage level or Vuse see next figure for the two different modes To ensure that the current measurement is performed correctly the stress interval must be set to more than 70ms The Monitor time will be 30ms for less than 12 devices 50ms for more than 12 but less than 32 devices and 100ms for 32 or greater devices Figure 75 Timing diagram of a ramp step Stress Stress interval e
97. s the setting factor the device is considered to have failed the ramp test Post test When the ramp test is completed or exits due to breakdown a post ramp test is performed by applying a gate voltage Vpost and measuring the current Ipost If Ipost exceeds the fail current Iinit the device is considered to have failed the post test Failure mode According to the pass or fail criteria for the Initial Ramp and Post tests the failure modes are categorized in the next table Failure type Initial test BDtest Post test Initial type 1 Fail N A N A Catastrophic type 2 Pass Fail Fail Masked Catastrophic type 3 Pass Pass Fail Non catastrophic type 4 Pass Fail Pass Monitor fail type 5 N A Fail N A All pass type 6 Pass Pass Pass ACS2600RTM 900 01 Rev B December 2012 5 13 Section 5 Voltage ramp ACS 2600 RTM User s Manual Data recording The test results data are displayed on the Data tab and will be logged as a kdf db or csv file if run in the Automation mode Data for multiple Groups are displayed using multiple tabs within the Data tab The output data for different sub devices is distinguished by the parameter names The output 5 14 parameters for one group are in the following table Parameter Unit Comment Time_ lt sn gt S Time stamps _ lt pad gt _pre_ lt sn gt A Measured current in Pre test V_ lt pad gt
98. s Fail Non catastrophic type 4 Pass Fail Pass Monitor fail type 5 N A Fail N A All pass type 6 Pass Pass Pass Data recording The data test results are displayed in the Data tab and will be logged in the kdf db or the csv file if executed in Automation mode The data for multiple groups is displayed in multiple tabs within the Data tab The output data for sub devices is distinguished by the parameter name suffixes The output parameters for one group are shown in the next table Parameter Unit Comment Time_stress_ lt sn gt S Stress phase time stamps Time_meas_ lt sn gt S Measure phase time stamps _ lt pad gt _pre_ lt sn gt A Measured current in Pre test _ lt pad gt _post_ lt sn gt A Measured current in Post test V_SILC_ lt sn gt V Applied voltage at SILC test _SILC_check_ lt sn gt A Measured current at Vcheck when SILC test is set as sweep voltage _SILC_ lt sn gt A Measured current in SILC test _ lt pad gt _use1_ lt sn gt A Measured current under Vuse1 in measure phase lt pad gt can be gate drain or source _ lt pad gt _use2_ lt sn gt A Measured current under Vuse2 in measure phase lt pad gt can be gate drain or source Inoise_ lt pad gt A Noise level of the gate current for soft breakdown judgment _ lt pad gt A Monitor gate current at stress phase Q_ lt pad gt C Accumulated gate charge Tbd_ lt sn gt S Breakdown time BD_type_ lt sn gt B
99. s contaminated and operation is affected the board should be returned to the factory for proper cleaning servicing Safety precaution revision of November 2012 Table of Contents ACS 26000 RTM AR 1 1 A A a a a a E ia 1 1 WER and ACS 2600 RTM Overview sai ii 1 2 INStruMeNnt CONnMECHON SCHEING uni 1 3 Sequential amd paralelas iia 1 6 Sequental versus paralela codos cities co ll in thi lo 1 7 ACS 2600 based RTM general Settings esiianicinic iniciada 1 8 AURA NEWS coo pata ceees eats alcoi 1 8 Device Seting O ESO A 1 9 Add anew RTM scienee ia a nd 1 10 Test mod le Settings cercar rica Is 1 11 Runa 26000 based RIMI ionieni a aa ee aien aeaa a a ie le dre S aE 1 12 Preference SetIngS ainia lr 1 13 Data logging sumidos e a E iio 1 14 Data analVsIS ea list 1 19 ICU and NB Ticas 2 1 TES PHINCIPIG ses cetonas 2 1 Instrument connecti Miseria 2 3 WeSUNOW uia data a a a a a a a aid 2 4 Se ii ed E E E mindeduateita 2 6 PresStress Tests Settings viii iia aaa 2 7 MESS SO UMS tiesto o a a 2 10 Measure Send salsa 2 13 P st Stress TESS sci isideicciccciacacduedcolapsnasdieidelopianccasiceibel apis bescot ce delay apccusieeteriayuenceeetiwiaenen wis 2 13 Preference Seto iria li lia ee 2 14 Globalvaables tu iio 2 15 Formulat rss ira 2 16 Parameter extraction UNeiONS elssocoticiacini s islas tija acia 2 17 Data TOCO Gusssscn sasarcis E lisas dias lada aldo so 2 23 Fast NB li iia 3 1 TeSt PARCIPI E id 3 1 Sequential Versus parallel mii A AA
100. s the measured current at loop n e dRact is the resistance of the protection resistor High capacitance mode In some cases the device under test DUT has high capacitance for example in a high power device therefore the SMU should be set to high capacitance mode for better measurement When high capacitance mode is enabled a minimum load capacitance of 100 nF is recommended In absence of this minimum load capacitance overshoot and ringing may occur In order to enable high capacitance select the Enable High Capacitance mode option see the next figure Also the SMU low range and current compliance value must be greater than or equal to 1e 6 For more details about the Series 2600B instrument high capacitance mode refer to the Series 2600B Reference manual Figure 61 Enabled high capacitance mode IV Enable High Capacitance mode 4 12 ACS2600RTM 900 01 Rev B December 2012 ACS 2600 RTM User s Manual Section 4 Time dependent dielectric breakdown Device and SMU settings The device and SMU settings are all set at the device level For example all of the devices and SMUs that are assigned in the device level of the test tree such as the Group No Dev No SMU and Terminal are shown in the next figure W um L um the MOSFET device dimensions These parameters are used to calculate the gate current density and charge density Compl the current compliance limit value Stress V Only available for the gate terminal
101. sn gt Ohm Calculated DUT resistance _heat_ lt sn gt A Heat current Power_ lt sn gt WwW Calculated power TCR_Tchuck_ lt sn gt K TCR value at chuck temperature Rinit_Tchuck_poly_ lt sn gt Ohm Poly heater resistance at chuck temperature Rinit_Tchuck_dut_ lt sn gt Ohm DUT resistance at chuck temperature Rtest_poly__ lt sn gt Ohm Poly heater resistance when phase 3 begins Rtest_dut_ lt sn gt Ohm DUT resistance when phase 3 begins Ptest_ lt sn gt Ohm Power when phase 3 begins Jtest_ lt sn gt Alem Current density when phase 3 begins t_P3begin_ lt sn gt S Time when phase 3 begins Twarn_ lt sn gt S The time when resistance reaches the warning value time is recorded from the start of t_P3begin TTF_ lt sn gt S Failure time from t_P3begin Failtime_ lt sn gt S Failure time from test beginning Rend_Tchuck_poly_ lt sn gt Ohm Poly heater resistance at chuck temperature in post fail measurement Rend_Tchuck_dut_ lt sn gt Ohm Poly heater resistance at chuck temperature in post fail measurement lt sn gt the number of the sub device ACS2600RTM 900 01 Rev B December 2012 Specifications are subject to change without notice All Keithley trademarks and trade names are the property of Keithley Instruments Inc All other trademarks and trade names are the property of their respective companies KEITHLEY A GIR EAT EIR MEASURE G F C0 NF TD EN E E Keithley Instruments Inc Corporate Headquarters 28775 Auror
102. sn gt V In pre stress test measure phase post stress for example V_Drain_1_pre0_1 test the forcing voltage value of certain test step V_Gate_1_meas1_1 Sweep points are all listed _ lt pad gt _ lt test step name gt _ lt sn gt A In pre stress test measure phase post stress for example _Drain_1_pre0_1 test the measured current value of certain test _Gate_1_meas1_1 step Sweep points are all listed lt Param gt _ lt pad gt _ lt sn gt The calculated formula parameter value Param is the parameter name defined in the formulator NOTE lt sn gt is number of sub devices lt pad gt is the pad name ACS2600RTM 900 01 Rev B December 2012 2 23 Section 3 Fast NBTI In this section e aaceecasattaay A acetone eeeus 3 1 Sequential versus parallel iccicsaccciiaiscianiesesvedeaigesanyetecsescatprtentk 3 2 Measure phase MING cscicsntaic iiai 3 2 POSE RAW dala sos c2ccis sacecsissace ceca RAE AES 3 5 Test principle The negative bias temperature instability NBTI test NBTI_FAST_ SWITCHING is used to obtain the degradation of a MOSFET device for a duration of time and under stress The NBTI_FAST_SWITCHING test is the same as the HCI NBTI test However when the stress is off the device will recover to heal the degradation which possibly leads to a more optimistic lifetime prediction The NBTI_FAST_SWITCHING test uses several methods to minimum the recover time In the measure phase NBTI_FAST_SWIT
103. te percent as compared to the previous value the limit value will change Limit Percent the limit value will be set as the 100 Limit Percent multiplier of the measured gate current 4 10 ACS2600RTM 900 01 Rev B December 2012 ACS 2600 RTM User s Manual Section 4 Time dependent dielectric breakdown Stress voltage compensation setting In some cases for instance when testing high power devices a protection resistor is inserted in series with the SMU in order to prevent the rush current at break down point and prevent oscillation The inserted protection resistor will cause a voltage drop which means the SMU forcing voltage should be compensated in order to maintain a constant voltage stress on the device To get the desired stress voltage on the device the SMU forcing voltage should make a compensation to achieve the proper value The voltage compensation has two phases e Initial speed up loop at the start of the stress e Voltage compensation during the stress Initial speed up loop At the start of the stress an initial speed up loop is used to get the voltage on the device under test Vdut close to the desired stress voltage Vtarget If the absolute value of Vdut Vtarget is greater than the Voltage Gap user specified then the loop will continue if it is less than the Voltage Gap the loop will end Voltage compensation The voltage compensation during the stress will calculate the next force voltag
104. the csv file above and open in an external tool like Excel auto_update_manual_run_plot 0 Manually update the graph by Reflesh button See detail below Copy the csv file above and open in an external tool like Excel Abort operation or unexpected crash Secure data by copying the csv file above ACS2600RTM 900 01 Rev B December 2012 ACS 2600 RTM User s Manual Section 1 ACS 2600 RTM Occasionally some 2600 based RTM tests can be used for long term testing several days or even several weeks This long term testing is used to gather a tremendous amount of data in order to analyze the data For the purpose of data security when you manually conduct tests ACS will automatically log the data to a csv file and a csvbak file over a period of time The csv file logs all of the current data results while the csvbak file logs the data results since the last time the data was saved manually Note that when you update and save a csv file it will overwrite the previous file this includes the csvbak file Both of the temporary files csv and csvbak are located at the following default location on your computer ACS Projects lt project name gt temp lt test_module_name gt csv ACS Projects lt project name gt temp lt test_module_name gt csvbak However if you select the Save All function on the tool bar the csv file will be permanently saved to the following default location on your computer ACS Pr
105. the device after the stress stage The VRamp test provides a ramped voltage stress that is able to set up to five segments Each voltage ramp is able to set its own ramp rate This test is appropriate for finding the breakdown voltage of a test structure Figure 64 VRamp test result diagram log l gate Current noise level ______ AAA Break Down Voltage Vgate Section 5 Voltage ramp ACS 2600 RTM User s Manual Instrument connection The VRamp test applies ramped voltages to the gate and bulk and the source and drain are connected to ground GND The test module uses the Series 2600B or Series 2600 SourceMeters The SourceMeters can be setup for different groups GPIB or Ethernet for parallel testing Within each group you can also setup multiple sub devices for sequential or parallel testing In a parallel test each sub device will be set as a sub group DTNS Group The SourceMeters connected together within a group must have the same firmware The 2600B SourceMeters and the 2600 SourceMeters for instance the A and non A versions cannot be used together A typical connection scheme is shown in the next figure Figure 65 A typical instrument connection scheme GPIB Cables Or TSP LINK Subordinate Node3 Subordinate Node3 EETETTETTETELTELELITELEELEI dnog SNLG Buowe Hujuurnu eed Subordinate Node 4 dnog SNLG Buowe Hujuuni Peed Gr
106. the file types to save for data analysis you will have to open the Preferences dialog box in the Tools drop down menu and go to the Automation Settings tab see next figure Figure 12 Preferences on the Automation Settings tab Save db file setting Save kdf file setting Save tm p file for 2600 based RTM TOW Se irr ACS2600RTM 900 01 Rev B December 2012 1 15 Section 1 ACS 2600 RTM ACS 2600 RTM User s Manual In the Automation panel go to the Data tab and select the Automatically save to CSV file after each wafer and you can select the Automatically save to CSV file after each site see next figure Figure 13 Automation panel Data tab Eile Edit View Operation Tools Help Data For Current Wafer Test Process Level T4 Fixture ID Equipment ID Laser ID Name X um Y um Device Name Test Name ameter Nan Target 4 Automation panel Data tab Keithley S500 4 5 6 7 8 9 10 1 12 13 14 15 sa 4 Save csv file setting Automatically save to CSV file after each wafer M Automaticaly save to CSV file after each site Y Parameter in Manually update data Keithley Instruments Inc Event Security service or possible options Real time data save temp lt test_module_name gt csv temp lt test_module_name gt csvbak Progress monitor auto_update_manual_run_plot 1 Automatically update the graph on ACS data tab Copy
107. tion 2 HCI and NBTI ACS 2600 RTM User s Manual You can configure the timing settings in the Time Setting dialog box as shown in the following figure Figure 23 Timing Setting 2 8 ACS2600RTM 900 01 Rev B December 2012 ACS 2600 RTM User s Manual Section 2 HCl and NBTI The Timing Setting parameters descriptions Source Range sets the voltage source range to auto best fixed or a fixed range e Best fixed sets the source range to a force voltage x1 01 in a sample test or the highest sweep voltage absolute value x1 01 in a sweep test Meas Range sets the current measure range to auto best fixed or a fixed range e Best fixed sets the measure range to auto range in a sample test Or it sets the highest current absolute value x1 01 in a sweep test The highest current is measured by forcing the highest voltage in the sweep prior to the sweep test This will introduce a trial test before the sweep to find the best fixed measure range PLC power line cycle 0 001 25 Sweep Delay delay time between sweep points Hold Time hold time before the sweep Test Interval delay time before this test step NOTE If you set the Source Range and the Meas Range to a fixed range it will increase the sweep speed Figure 24 Measure sequence diagram Test Interval Hold Time Stress Stress Subdevice_1 Subdevice_2 PES Output Off 1 1 i ACS2600RTM 900 01 Rev B December 20
108. ts of dielectric at lower electrical fields e JRamp TDDB_CCS Ramped current JRamp test and time dependent dielectric breakdown TDDB under constant current stress CCS JRamp uses a ramped current stress on capacitors or gate oxides to characterize the defects of dielectric at higher electrical fields The JRamp is also able to achieve the bounded JRamp test provided that the current is set to ramp up to a specified level and then held until breakdown The bounded JRamp test provides a very repeatable charge to breakdown Qbd measurement The TDDB_CCS uses constant current as stress to the oxide 3 Metal e lso EM Isothermal electromigration test This test is used to determine the relative rate of electromigration in a metal line at a specified stress temperature Also this test induces a temperature in the metal line by joule heating at a high current density e Poly_Heater The poly heater test has the same test flow as the Iso_EM test The difference between Iso_EM and Poly_Heater is that the Iso_EM uses the DUT device under test itself to generate the heat and the Poly_Heater uses another poly material as a heater to heat the DUT All of the 2600 based RTM tests HCI NBTI NBTI_FAST_SWITCHING TDDB_CVS VRamp JRamp TDDB_CCS Iso_EM and Poly_Heater use Keithley Instruments Series 2600B or Series 2600 SourceMeters They are specifically optimized for SMUs with a per pin connection scheme for better test throughput The test algo
109. ub devices The next figure a shows the device type list and the sub devices Also the Image Browser b shows the CUSTOM devices list which contains multiple sub devices All of the multiple sub devices are appropriate for the ACS 2600 RTM tests Figure 6 Select a device type Folder Patterns Fles of type emp bro e A MN Partern_1 mj M Hone arre PolyHeater 2Wre Resstor PolHexter 4Wre Resstor ldmos brr 1 8 ACS2600RTM 900 01 Rev B December 2012 ACS 2600 RTM User s Manual Section 1 ACS 2600 RTM Device setting The settings on the Device Settings tab will determine the test that runs in an instrument configuration The settings must be consistent with the real instrument connection Figure 7 The Device Settings tab Select Groups GPIB Group or Ethernet Group The test modules under this device will be operated parallel among the Groups Set for each Pad Sub Device number SMU number Pad Name Select Sub devices for the pad If a 2600 based RTM test is parallel the test will be operated parallel according to DTNS group Each sub device is set as a DTNS group ACS2600RTM 900 01 Rev B December 2012 1 9 Section 1 ACS 2600 RTM ACS 2600 RTM User s Manual If you have selected multiple groups the instrument s configuration in each group must be the same including the instrument model For example if there are three Model 2636As in group 1 th
110. urceMeters can be arranged in multiple groups GPIB or Ethernet to allow for parallel testing Within each group you can also setup multiple sub devices for sequential or parallel testing With the parallel testing each sub device is set as a sub group DTNS Group The SourceMeters in a connection scheme must have the same firmware The 2600B SourceMeters and the 2600 SourceMeters for instance the A and non A versions cannot be used together A typical connection scheme is shown in the next figure A typical connection scheme is below two GPIB or Ethernet Groups Group 1 and 2 each Group has 3 instruments Node 1 Master and 2 are set DTNS group 1 sub group 1 Node 3 and 4 are set DTNS group 2 sub group 2 Figure 18 A typical instrument connection scheme GPIB Cables Or TSP LINK Subordinate Node3 Subordinate Node3 e e hrnsrnrrrrnsrrarnsnssssn st dnoi5 SNLG Buowe Bujuuny jefe sed Subordinate Node 4 dnog SNLG Buowe Hujuuni 9 e 1e d Group 1 Group 2 e oo oe el Parallel running among GPIB or Ethemet Group ACS2600RTM 900 01 Rev B December 2012 2 3 Section 2 HCl and NBTI ACS 2600 RTM User s Manual Test flow The HCI NBTI test flow is based on the following P Channel MOSFET procedures and standards JESD90 JESD60A JESD28 A The integrated test flow is shown in the next figure Figure 19 Test flow of HCI_NBTI test
111. vailable formula functions If the test step is a one point test only these functions are available VADD VDIV VMULT VSUB If the test step is a sweep test all of the functions are available GMMAX Purpose return the maximum transconductance also known as mutual conductance from _DRAIN and V_GATE Format GMMAX 1_DRAIN V_GATE Figure 33 GMMAX parameters aa Value gm_max maximum slope vg Example Gmmax GMMAX I DRAIN V_GATE MAX Purpose return the maximum value of the data array Format MAX X MIN Purpose return the minimum value of the data array Format MIN X PCTSHIFT_TO Purpose return the shift percentage from TO measurement of the value Format PCTSHIFT TO PAR ACS2600RTM 900 01 Rev B December 2012 2 17 Section 2 HCl and NBTI ACS 2600 RTM User s Manual POWB Purpose return the data or data array which is the power value calculated by a constant BASE and an index or index array VPOW Format POWB BASE VPOW BASE the base value VPOW one data or data array If VPOW is one data the return value is one single data If VPOW is a data array the return value is a data array with the same length and one to one correspondent to VPOW Example V2pow POWB 2 V_DRAIN SS Purpose extract the sub threshold swing between a certain duration of current START_lto STOP_1 Format SS I DRAIN V_GATE START _1 STOP 1
112. value the device has failed by definition e Soft Breakdown Limit the soft breakdown judgment factor The soft breakdown judgment is made by calculating the current noise using the last five measured monitor currents and then checking if the current noise setting Soft Breakdown Limit times are larger than the baseline noise The calculation of the current noise and noise baseline is referred to JESD92 SILC stress induced leakage current Limits the breakdown settings for the SILC test e Jmax the maximum current density If the SILC current density exceeds this value the device has failed by definition e J JO the current density change ratio compared to the first value If the SILC current density change ratio exceeds this value the device has failed by definition e J Jpre the current density change ratio compared to the previous value If the SILC current density change ratio exceeds this value the device has failed by definition ACS2600RTM 900 01 Rev B December 2012 4 7 Section 4 Time dependent dielectric breakdown ACS 2600 RTM User s Manual Pre Post Test breakdown of settings for the Pre test and Post test e Jmax the maximum current density If the Pre test current or Post test current densities exceed this value the device has failed by definition e Jmax the minimum current density If the Pre test current or Post test current densities are lower than this value the device has failed by definition
113. we Bujuuny ape sed Subordinate Node4 bonsrrrrrrrrrrrrrss dno19 SNLG Buowe Bujuuny Peed e J Parallel running among GPIB or Ethemet Group 7 2 ACS2600RTM 900 01 Rev B December 2012 ACS 2600 RTM User s Manual Section 7 Electromigration Test flow The Iso_EM test flow is based on the JEDEC standard JESD61A 01 see next figure Figure 89 Test flow of Iso_EM Meas R a Tchuck Cale Rth TO Meas R time Cale T P N Y Meas R Tchuck ACS2600RTM 900 01 Rev B December 2012 7 3 Section 7 Electromigration ACS 2600 RTM User s Manual According to the JEDEC Standard JESD61A 01 the test contains five parts 1 2 3 4 5 Determination of R at chuck temperature Initialization phase Temperature staircase and convergence phase Stress phase Post fail measurement The temperature is increased during the 2nd and the 3rd part of the test and is kept constant during the 4th part The detailed algorithm can be found in the JEDEC standard document During the entire process the test is performed by forcing a current and measuring the resultant voltage R is calculated using Ohm s Law and the temperature is calculated using the TCR temperature coefficient of resistance A Determination of R at chuck temperature In this part a small current linit is forced through the resistor in both polarities and R is measured and averaged If the average R value exceeds the given crit
114. www keithley com ACS 2600 RTM User s Manual ACS2600RTM 900 01 Rev B December 2012 MNN ACS2600RTM 900 01 KEITHLEY A GREATER MEAS URE OF CONFIDENCE ACS 2600 RTM User s Manual O 2011 2012 Keithley Instruments Inc Cleveland Ohio U S A All rights reserved Any unauthorized reproduction photocopy or use of the information herein in whole or in part without the prior written approval of Keithley Instruments Inc is strictly prohibited All Keithley Instruments product names are trademarks or registered trademarks of Keithley Instruments Inc Other brand names are trademarks or registered trademarks of their respective holders Document number ACS2600RTM 900 01 Rev B December 2012 KEITHLEY A Tektronix Company Safety preca utions The following safety precautions should be observed before using this product and any associated instrumentation Although some instruments and accessories would normally be used with nonhazardous voltages there are situations where hazardous conditions may be present This product is intended for use by qualified personnel who recognize shock hazards and are familiar with the safety precautions required to avoid possible injury Read and follow all installation operation and maintenance information carefully before using the product Refer to the user documentation for complete product specifications If the product is used in a manner not specified the protection prov
115. y a p channel MOSFET which is thermally activated may affect the PMOS device reliability with the manifestation of increased threshold voltage The temperature of the DUT is usually controlled by a hot chuck on a probe station The electric test procedures of HCI and NBTI are identical The Series 2600A and Series 2600 SourceMeters are used to implement the HCI NBTI test The next figure shows parameter changes to the MOSFET over stress time For example the threshold voltage which increases with the stress time affects the MOSFET parameters Section 2 HCl and NBTI ACS 2600 RTM User s Manual Figure 17 MOSFET threshold voltage Threshold Voltage Degradation Idrai Stress time 0 N Specified Current constant current method Stress time XX Vt shift Stress tim 0 Stress time XX Vgate The HCI NBTI test has three stages pre stress test stress measure sequence and post stress test The pre stress test verifies the functionality of the device the stress measure sequence applies a constant voltage stress to the device and measures the parameter changes And the post stress test characterizes the device after the stress stage The stress measure sequence has two phases stress phase and measure phase 2 2 ACS2600RTM 900 01 Rev B December 2012 ACS 2600 RTM User s Manual Section 2 HCl and NBTI Instrument connection The HCI NBTI test uses the Series 2600B or Series 2600 SourceMeters Multiple So
116. you have test data that is logged and saved you can find the data files in the following locations depending on what kind of test is run and the file type that is created Also the path for all of the ACS log files will have the following path as a prefix where C is the computer hard drive C ACS Projects lt Project_Name gt Test type File type File path Comments Manual CSV temp lt test_module_name gt csv The temporary csv data file data lt test_module_name gt csv The location of the csv file if you click Save All function csvbak temp lt test_module_name gt csvbak The backup file in case there is an error when saving the csv file Automated csv csv lt Lotname gt _WaferlInfo Wafer_1_ lt time gt csv Comma separated value format csv lt Lotname gt _WaferlInfo Wafer_1 Site_n1p1_ lt time gt c sv db db lt Lotname gt db Binary format file can be imported to KDAT Keithley Data Analysis Tool for advanced data analysis kdf kdf lt Lotname gt kdf Keithley Data Format file can be imported to ACS wafer level plot and statistics for analysis tmp RTM_temp curdata_ lt date and time gt tmp Temporary data file in case of data logging error realtime csv Realtime_Data Realtime_Data_ lt date and time gt csv Log the realtime plot data ACS2600RTM 900 01 Rev B December 2012 ACS 2600 RTM User s Manual Section 1 ACS 2600 RTM If you want to configure and enable

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