Presentation given by OptimalTest at Teradyne Users\' Group (TUG) in May, 2010

1. Advanced Adaptive Test – TTR for IGXL Platforms Lisa Vallerie, OptimalTest Lisa.Vallerie@OptimalTest.com Itai BenJacob, OptimalTestItai.BenJacob@OptimalTest.com

2. Agenda Introduction to Advanced Adaptive Test for Test Time Reduction Adaptive Test Time Reduction Methodologies Advantages on Teradyne FLEX IGXL platform 2

3. linked reports OptimalTest Database 3

4. Evolution of Test Optimization Static Test Optimization requires as much as months based on off-line analysis and is driven manually with point solution tools – or without tools altogether Dynamic Test Optimization is needed for overall manufacturing test efficiency to improve IC production and to increase yield learning Adaptive Test Optimization is a dynamic method of managing process variations while eliminating redundancies in real- or near- realtime; both statistical and automated process control methodologies are used 4

5. Adaptive Test ITRS Definition Adaptive Test is a broad term used to describe methods that change test conditions, test flow, test content and test limits (potentially at the die/unit or sub-die level) based on manufacturing test data and statistical data analysis This includes feed-forward data from in-line test and early test steps to later test steps and feed-back data from post-test statistical analysis that is used to optimize testing of future products Adaptive Test includes realtime & near-realtime data analysis that can perform Statistical Process Control (SPC) and adjust test limits and content during production testing on-the-fly 5

6. Adaptive Test Flow A&O: Analysis & Optimization Test Database & Automated Data Analysis Fab Data Design Data Business Data Customer Specs 6

7. Benefitsof Advanced Adaptive Test Lower test costs – Decreased test times due to algorithmic test automation vs. legacy solutions Higher yields – Early detection of yield degradation accelerates root cause isolation and yield improvement on future devices. Better Quality & Reliability – Identification of outlier devices that result in infant mortality, improved test and device quality through enhanced process control 7

9. P/F Method – performed on low fallout testsLeverage information from actual & historic device test results Applicable at WS and FT Selection is based on device & test characteristics and needs Can be applied simultaneously or individually Patents pending & issued 8

11. Parametric TTR Algorithm Flow in RealTime 10

12. Adaptive Parametric TTR Algorithm Terminology “Predicted Test Ranges” – calculated based on the actual parametric test measurement results. TTR is only enabled when within the Spec Limits. “Predicted Test Ranges” are (re)-evaluated after “Validation Units” and “Sampling Units” are tested, using the data from these units. Provide a “safety margin” for product quality. OT’s method imposes a “Safety Coefficient” used in the calculation of the ranges to insure the maximum safety of the TTR process. Customer specifies acceptable DPPM 11

13. Adaptive Parametric TTR Algorithm Terminology Algorithms’ parameters are user according to the desirable TTR level and DPPM “risk” User Configurable Variables are: Validation Unit Quantity Sampling Unit Rate Safety Coefficient (acceptable DPPM) Quantity of units used to evaluate the optimal Predicted Test Ranges 12

14. Customer’s Upper Spec Limit OT’s Upper Predicted Test Range Actual Parametric Test Results (normal lot) Test Value Test Value OT’s Lower Predicted Test Range Customer’s Lower Spec Limit Touch Down Sequence Parametric TTR Simulation 1TTR enabled across an entire lot 13

15. Parametric TTR Simulation 2TTR disabled as measurements cross a threshold (lower spec limit) OT’s Upper Predicted Test Range Actual device “failures” Occur after TTR is disabled Test Value Customer’s Lower Spec Limit TTR is dynamically disabled OT’s Dynamically Calculated Lower Predicted Test Range falls below the Customer’s Lower Spec Limit 14

16. Parametric TTR Simulation 3TTR is not enabled when Validation Unitsfail to achieve Predicted Test Range OT’s Upper Predicted Test Range Actual device “failures” occur after TTR disable decision Test Value Customer’s Lower Spec Limit Validation Units TTR is not enabled for entire lot OT’s Dynamically Calculated Lower Predicted Test Range First Validation Unit falls below Customer’s Lower Spec Limit 15

17. Adaptive Pass / Fail TTR Algorithm Methodology Adaptive Pass / Fail TTR algorithm leverages Pass / Fail data in order to decide, in real-time, whether the “candidate test” can be turned off for Test Time Reduction Employs the same mechanism of “Validation Units” and “Sampling Rate” to insure the user’s confidence with diminished test suite(s) 16

18. In FT, the process is straight forward and is implemented as depicted below: For WS, additional dedicated techniques / algorithms support the special characteristics of Wafer/Sort Test Implementation of Adaptive TTR in WS and FT 17

19. Implementation of Adaptive TTR in WS and FT Reference Die – “the health of the wafer”: Die strategically selected according to various attributes Always tested with the full test-program (not TTR “eligible”) Results used by Adaptive TTR algorithm in real-time to enable / disable TTR on subsequent die of the wafer Applicable at Wafer Sort and Final Test (ULT required at FT) Validation Wafers – “the health of the lot”: Few sample wafers/lot Always tested with the full test-program (not TTR “eligible”) Results used by Adaptive TTR algorithm in real-time based on to enable / disable TTR on the rest of the wafers in the lot Reference Die & Validation Wafers used for “Quality Control” 18

20. Locations of Reference/Baseline Die are selected according to various algorithms: Next to E-test structures (for maximized correlation between test sockets) Spread-out equally in each of the 3 ring areas (for maximized coverage) In areas of different yield signatures In most of the lithography exposure locations In areas corresponding with Fabdefect sampled areas Implementation of Adaptive TTR Reference/Baseline Die 19

21. Adaptive TTR on IG-XL TestersTheory of Operation OptimalTest utilizes a compact code, “OTProxy” that can be installed on IGXL testers OTProxyuses a COM component (ActiveXTTRDLL) which is a VB6 code handling the Excel API in order to perform TTR (OTProxyuses this COM object to toggle test-flow Enable Words) This COM object is being registered to the system automatically as part of the OTProxy installation OTProxy’sactions are based on IG-XL Test Instances Running TTR on IG-XL requires a unique Test ID per test 20

22. Adaptive Test Solutions in Use 21

23. OTProxy Server TTR Actions IG-XL Tester OTProxyEngine Test Results TTR COM Object Enable Words and Macro Injection Component OTDF Datalog Test Mapping TTR Actions Skip Test List Adaptive TTR on IG-XL Tester Block Diagram 22

24. IG-XL Test Program Manipulationin Real Time Before injection of Enable Words After injection of Enable Words 23

25. Teradyne & OptimalTest Collaboration In 2009 Optimal Test and Teradyne announced a strategic alliance Teradyne’s Sales Force has been trained & has sales tools for use Ongoing technical exchanges with both R&D departments regarding Advanced Adaptive Test Techniques on the IGXL & Image platforms Business level exchange meetings on a monthly basis to leverage efforts to benefit key accounts Collaborating with Teradyne to Beta test our new test management solution ideas & to maintain roadmap coherence A key Teradyne fabless customer is currently deploying an end-to-end Advanced Adaptive Test solution across the supply chain 24

26. Increase Production Yield Improve Production Yield Speed Time to Entitled Yield Increase Product Reliability Optimize Overall Equipment Efficiency 1-4% Increase Product Reliability Through Outlier Detection Optimize Overall Equipment Efficiency (OEE) Speed Time to Actionable Data 20-50% 10-20% MEASURABLE RESULTS Improve Product & Testing Quality Reduce Test Times Advanced Adaptive Test for TTR and/or Improve Capital Utilization Increase Product & Testing Quality Reduce Customer Returns 10-30% 50-75% 25

27. Thank you! 26

28. Customer’s Upper Spec Limit OT’s Upper Predicted Test Range Actual Parametric Test Results (normal lot) Test Value Test Value OT’s Lower Predicted Test Range Customer’s Lower Spec Limit Touch Down Sequence 27

29. Back- up slides 28

30. Implementation of Adaptive TTR in WS and FT Reference Die are tested first to achieve a measure of overall wafer “Health” OTBox: reference die are tested before other die on the wafer OTProxy:a dedicated probing sequence is used Reference (or Baseline) Die Reference die are covered by US Patent 29

31. Adaptive Parametric TTR Algorithm Terminology “Validation Units” – the first “n” units of the lot / wafer These units are fully tested, TTR is not performed Typically “n” = 200-300 “Sampling Units” – after “Validation Units” are tested and TTR is enabled, one out of “x” units is being sampled Sampling Units are fully tested Typically “x” = 10-20 30

32. Adaptive TTR on IG-XL TestersTheory of Operation Test Mapping – Accomplished online via VB application which creates the test mapping file for the OTProxy Datalog (OTDF) triggers the test mapping tool automatically at the beginning of the lot / wafer Enable Words and macro injection are done online by the VB ActiveX DLL OT’s Enable Words injection method doesn’t overwrite the existing user defined Enable Words -- no change to test programs Those 2 operations are done at the beginning of the lot / wafer, after the Test-Program is loaded to the tester memory 31