Watchdog system having data differentiating means for use in monitoring of semiconductor wafer testing line

• US 5,726,920 A
• Filed: 09/29/1995
• Issued: 03/10/1998
• Est. Priority Date: 09/29/1995
• Status: Expired due to Term

• Current Assignee: Cypress Semiconductor Corporation (Infineon Technologies AG)
• Original Assignee: Advanced Micro Devices, Inc.
• Inventors: Chen, Susan Hsuching, Shiau, Ying, Lee, Chern-Jiann
• Primary Examiner(s): Voeltz, Emanuel T.
• Assistant Examiner(s): Bui, Bryan
• Application Number:
  US08/537,116
• Time in Patent Office: 893 Days
• Field of Search: 364/579, 364/552, 437/8, 437/180, 437/209, 437/51, 324/158.1, 324/73.1, 324/500, 324/537, 324/765, 360/25, 360/31, 357/40
• US Class Current: 702/108
• CPC Class Codes: G01R 31/2831 Testing of materials or semi-finished products, e.g. semiconductor wafers or substrates G01R31/318511 takes precedence; testing during manufacture H01L22/00
• CPC Class Codes: G01R 31/2851 Testing of integrated circuits [IC] G01R31/317 takes precedence; testing individual devices G01R31/26; testing printed circuits G01R31/2801

Abstract

In a final wafer sort (FWS) testing facility, the raw log-out data that is output by FWS test stations is augmented with additional differentiating data to thereby produce differentiable log-outs that can be sorted according to a variety of criteria including: product number or product family, time of test, specific wafer, specific production lot, intra-reticle site number, machine operator, and the specific swappable units of equipment that participated in the FWS testing. The differentiable log-outs are stored in a database and are periodically accessed by an automatic watchdog system that tests for exception conditions calling for immediate or long-term response. Corresponding alarm signals and trend reports are automatically generated and distributed to responsible personnel and/or reactive machine-systems as appropriate. The alarm distribution mechanism includes automatic paging of personnel by wireless beeper and/or e-mail. Immediate response alarms include exception conditions detected for accumulated bin counts on a per-wafer or per-lot basis. Long term alert reports include those that detect increased error rates and possible wear down of replaceable probe cards.

Claims

1. A machine-implemented watchdog system for monitoring the operations of one or more units of final wafer sort (FWS) test equipment, where each unit of FWS test equipment participates as part of one or more FWS test stations in FWS testing of plural dice provided on each of a supplied plurality of wafers from a given production lot of wafers, said FWS testing being for verifying high-level functionality of the tested dice, wherein each FWS test station outputs for each wafer tested by said test station, a corresponding block of raw result data indicative of which dice tested as functional or not, said system comprising:

(a) receiving means for receiving respective blocks of raw result data from each respective test station, each received block of raw result data indicating FWS test results obtained by the respective test station for a respectively tested wafer;

(b) differentiating means for adding to each received block of raw result data, additional information signals, said additional information signals enabling the sorting of the blocks of raw result data according to one or more predefined sorting criteria, the combination of each block of raw result data and the correspondingly added additional information signals defining differentiable result data; and

(c) storing means for storing the differentiable result data.

2. The machine-implemented watchdog system of claim 1 wherein said additional information signals include a product_-- identifier field for identifying a product-line or a specific product within a given product line to which the tested wafer belongs and with which the respectively received block of raw result data is to be associated.

3. The machine-implemented watchdog system of claim 1 wherein said additional information signals include a lot_-- number field for identifying a specific cassette or lot of wafers that are being tested together and to which the tested wafer belongs and with which the respectively received block of raw result data is to be associated.

4. The machine-implemented watchdog system of claim 3 wherein said additional information signals further includes a wafer_-- number field for uniquely distinguishing the tested wafer from the remaining wafers of said cassette or lot of wafers.

5. The machine-implemented watchdog system of claim 1 wherein said additional information signals includes a operator_-- identification field for identifying a specific machine operator responsible for operating the respective test station from which the respectively received block of raw result data is obtained.

6. The machine-implemented watchdog system of claim 1 wherein said additional information signals includes a date_-- of_-- test-run field for identifying the date on which the FWS testing was performed to produce said received block of raw result data.

7. The machine-implemented watchdog system of claim 6 wherein said additional information signals further includes a start_-- time_-- of_-- test-run field for identifying the time within said date at which the FWS testing was begun to produce said received block of raw result data.

8. The machine-implemented watchdog system of claim 1 wherein:

(d.1) the respective test station of each received block of raw result data includes and uses a specific prober unit and a set of probes for carrying out said FWS testing, the prober unit being for bringing each respective wafer-under-test into alignment with the corresponding set of probes; and

(b.1) said additional information signals includes a prober_-- equipment_-- identification field for identifying the specific prober unit used during the FWS testing that produced said received block of raw result data.

9. The machine-implemented watchdog system of claim 8 further wherein:

(d.2) each prober unit is programmably configurable for stepping through differing arrangements of dice on each wafer; and

(b.2) said additional information signals includes a prober_-- setup_-- configuration data block for identifying a specific stepping arrangement loaded into the programmably configurable prober unit during the FWS testing that produced said received block of raw result data.

10. The machine-implemented watchdog system of claim 1 wherein:

(d.1) the respective test station of each received block of raw result data includes and uses a mainframe unit for controlling the carrying out said FWS testing and a preceding setup procedure; and

(b.1) said additional information signals includes a setup_-- control_-- file_-- pathname field for identifying a specific control data file to be commonly used by the mainframe unit for controlling the testing of each die during setup or subsequent FWS testing of a production lot of wafers.

11. The machine-implemented watchdog system of claim 1 wherein:

(d.1) the respective test station of each received block of raw result data includes and uses specific pieces of generic probe head equipment and a mainframe unit for carrying out said FWS testing, the generic probe head equipment being for operatively coupling the mainframe unit to the wafer-under-test via additional product-specific equipment; and

(b.1) said additional information signals includes a test_-- system_-- identification field for identifying the specific pieces of generic probe head equipment used for carrying out said FWS testing.

12. The machine-implemented watchdog system of claim 1 wherein:

(d.1) the respective test station of each received block of raw result data includes and uses a mainframe unit for controlling the carrying out said FWS testing and a preceding setup procedure; and

(b.1) said additional information signals includes a test_-- procedure_-- identification field for identifying a specific test program to be executed by the mainframe unit for generating said received block of raw result data.

13. The machine-implemented watchdog system of claim 1 wherein:

(d.1) the respective test station of each received block of raw result data includes and uses a product-specific probe card as part of the one or more units FWS test equipment for carrying out said FWS testing, the product-specific probe card being for interfacing with a wafer-under-test having dice of a specific product; and

(b.1) said additional information signals includes a probe-card_-- identification field for identifying the product-specific probe card used during the FWS testing that produced said received block of raw result data.

14. The machine-implemented watchdog system of claim 13 further wherein:

(b.2) said additional information signals includes a date_-- of_-- test-run field for identifying the date on which the FWS testing was performed to produce said received block of raw result data.

15. The machine-implemented watchdog system of claim 1 wherein:

(d.1) a production line monitoring system tracks work-flow progress for each respective lot of wafers to which the respective wafer of each received block of raw result data belongs; and

(b.1) said additional information signals includes a releasable_-- workstream_-- control_-- number field for conditional release to said production line monitoring system upon determination that the FWS testing performed to produce said received block of raw result data was properly performed.

16. The machine-implemented watchdog system of claim 1 further comprising:

(d) data correlator means, responsive to said additional information signals of said differentiable result data, for segregating the corresponding blocks of raw result data according to one or more of the predefined sorting criteria and routing the segregated blocks of raw result data to correspondingly segregated collection bins.

17. The machine-implemented watchdog system of claim 16 further comprising:

(e) a plurality of exception-condition defining modules, each corresponding to one of said segregated collection bins, for defining exception-conditions which when satisfied, warrant an exception-handling reaction; and

(f) comparator means for testing data collected in each of said segregated collection bins against the exception-conditions defined by a respective one of said exception-condition defining modules and for automatically initiating a respective one or more exception-handling reactions when a respective one or more of the exception-conditions is satisfied.

18. The machine-implemented watchdog system of claim 17 wherein:

(f.1) the respective test station of each received block of raw result data forwards each respectively-tested wafer to a programmably-preconfigured wafer disposition/inking station for subsequent and automatic processing of the forwarded wafer; and

(f.2) said automatically initiated exception-handling reactions include re-instructing the wafer disposition/inking station regarding the subsequent and automatic processing of the forwarded wafer in the case where a respective exception-condition is satisfied for said wafer and the satisfied exception-condition is predesignated as calling for said re-instructing of the wafer disposition/inking station.

19. The machine-implemented watchdog system of claim 17 wherein said automatically initiated exception-handling reactions include generation of an alarm signal in the case where a respective exception-condition is satisfied and the satisfied exception-condition is predesignated as calling for said alarm signal.

20. The machine-implemented watchdog system of claim 17 wherein said automatically initiated exception-handling reactions include generation of a trend report in the case where a respective exception-condition is satisfied and the satisfied exception-condition is predesignated as calling for said trend report.

21. The machine-implemented watchdog system of claim 17 wherein said automatically initiated exception-handling reactions include generation of an automatic shutdown control instruction in the case where a respective exception-condition is satisfied and the satisfied exception-condition is predesignated as calling for said shutdown control instruction.

22. The machine-implemented watchdog system of claim 1 wherein said additional information signals include reticle_-- area_-- configuration information for identifying an intra-reticle site number associated with each die on which the FWS testing was performed to produce said received block of raw result data.

23. A computer-readable data storage apparatus storing differentiable result data obtained from one or more final wafer sort (FWS) test stations, said data storage apparatus including:

(a) first means storing raw result data obtained from one or more final wafer sort tests run by respective ones of the FWS test stations on a corresponding one or more wafers; and

(b) second means storing wafer-identifying data identifying each unique wafer from which a correspondingly stored portion of said raw result data was produced.

24. A data storage apparatus according to claim 23 further comprising:

(c) third means storing test equipment identifying data identifying the FWS test station which produced the correspondingly stored raw test result data.

25. A data storage apparatus according to claim 24 further comprising:

(d) fourth means storing time-of-test data identifying the time at which a corresponding FWS test was run on said identified FWS test station for producing the corresponsingly raw test result data.

26. A data storage apparatus according to claim 23 further comprising:

(c) third means storing product identification data identifying a specific product or specific product line or specific lot of wafers that was tested to produce the the correspondingly stored raw test result data.

27. A data storage apparatus according to claim 23 further comprising:

(c) third means storing test equipment identifying data identifying one or more specific portions of a respective FWS test station which participated in the production of a correspondingly stored portion of the raw test result data.

28. A data storage apparatus according to claim 27 wherein:

the one or more final wafer sort (FWS) test stations include a replaceable, product-specific probe card; and

said test equipment identifying data identifies a specific probe card used for producing a corresponding stored portion of said raw result data.

29. A data storage apparatus according to claim 23 further comprising:

(c) third means storing operator_-- identification data identifying a specific machine operator responsible for operating a respective FWS test station from which a corresponding stored portion of said raw result data was obtained.

30. A data storage apparatus according to claim 23 wherein:

each FWS test station is programmably configurable for stepping through differing arrangements of dice on each wafer; and

said data storage apparatus further comprises;

(c) third means storing setup_-- configuration data identifying a specific stepping arrangement loaded into the programmably configurable FWS test station from which a corresponding stored portion of said raw result data was obtained.

31. A data storage apparatus according to claim 23 wherein:

each FWS test station is programmably configurable for carrying out different test procedures on supplied wafers; and

said data storage apparatus further comprises;

(c) third test_-- procedure_-- identification data identifying a specific test procedure that was performed and from which a corresponding stored portion of said raw result data was obtained.

32. A data storage apparatus according to claim 23 wherein:

each wafer includes a plurality of die arranged as tiled reticle areas, and

said data storage apparatus further comprises;

(c) third means storing reticle_-- area_-- configuration information identifying an intra-reticle site for each die on which the FWS testing was performed to produce a corresponding stored portion of said raw result data.

33. A machine-implemented test system comprising:

(a) collecting means for collecting blocks of raw log-out data from a respective one or more test stations;

(b) data differentiating means for adding differentiating information to each of the collected blocks of raw log-out data and for thereby producing differentiable log-out data, said differentiable log-out data being structured to enable differentiation of each of said blocks of raw log-out data according to one or more predefined sorting criteria;

(b) sorting means for sorting through the differentiable log-out data in accordance with one or more of said predefined sorting criteria and for thereby defining one or more groups of differentiated log-out data; and

(c) exception-condition detecting means for testing the one or more groups of differentiated log-out data against exception-conditions defined by a respective one or more exception-condition defining modules and for initiating a respective one or more exception-handling responses upon detection of the satisfaction of a respective one or more of said exception-conditions.

34. A machine-implemented test system according to claim 33 further comprising:

(d) alarm means responsive to the exception-condition detecting means for generating an alarm signal in response to satisfaction of a corresponding one or more of said exception-conditions that is pre-designated as warranting the issuance of said alarm signal.

35. A machine-implemented test system according to claim 33 further comprising:

(d) trend reporting means responsive to the exception-condition detecting means for generating a historical trend report in response to satisfaction of a corresponding one or more of said exception-conditions that is pre-designated as warranting the issuance of said historical trend report.

36. A machine-implemented test system according to claim 33 further comprising:

(d) shutdown control means responsive to the exception-condition detecting means for generating one or more shutdown commands to predefined ones of production equipment operating in conjunction with said test stations, said generation of the one or more shutdown commands being in response to satisfaction of a corresponding one or more of said exception-conditions that is pre-designated as warranting the issuance of said one or more shutdown commands.

37. A machine-implemented managing system for managing operations of a final wafer sort (FWS) testing facility having one or more test stations, said managing system comprising:

(a) first storage means for automatically collecting and storing blocks of differentiable log-out data obtained from respective testing of one or more wafers by a respective one or more of the FWS test stations, said differentiable log-out data being differentiable according to a plurality of predefined sorting criteria including product type and date of testing;

(b) second storage means for storing exception-definitions;

(c) sort-and-query means, operatively coupled to the first and second storage means, for automatically sorting through the stored, differentiable log-out data in accordance with one or more of said predefined sorting criteria, for thereby defining one or more groups of differentiated log-out data corresponding to the predefined sorting criteria, for automatically testing the one or more groups of differentiated log-out data against the stored exception-definitions, and for automatically detecting satisfaction of a respective one or more of said exception-conditions by the tested one or more groups of differentiated log-out data.

38. A machine-implemented managing system according to claim 37 wherein:

(c.1) the sort-and-query means is further for issuing alarm signals upon detection of the satisfaction of a respective one or more of said exception-conditions; and

the managing system further comprises;

(d) distribution control means, operatively coupled to the sort-and-query means, for distributing the issued alarm signals to predefined destinations.

39. A machine-implemented managing system according to claim 38 wherein the predefined destinations include a wireless beeper.

40. A machine-implemented managing system according to claim 38 wherein the predefined destinations include an electronic mailbox.

41. A machine-implemented managing system according to claim 37 further comprising:

(d) watchdog frequency control means, operatively coupled to the sort-and-query means, for defining a repeat rate at which the sort-and-query means is to repeatedly perform a respective one or more sort and query tasks.

42. A machine-implemented managing system according to claim 41 further comprising:

(e) task-list means, operatively coupled to the watchdog frequency control means and to the sort-and-query means, for storing a list of and thereby defining the one or more of the sort and query tasks that are to be repeatedly performed by the sort-and-query means.

43. A machine-implemented managing system according to claim 42 wherein the sort and query tasks of said task-list means includes:

(e.1) a first task command instructing the sort-and-query means to check the differentiable log-out data stored in the first storage means against corresponding ones of the stored exception-definitions on a per-wafer basis, said checking only covering differentiable log-out data belonging to a first predefined time period.

44. A machine-implemented managing system according to claim 43 wherein the sort and query tasks of said task-list means further includes:

(e.2) a second task command for instructing the sort-and-query means to secondly check the differentiable log-out data stored in the first storage means against corresponding ones of the stored exception-definitions on a per-lot basis, said checking only covering such secondly-checked differentiable log-out data belonging to a second predefined time period.

45. A machine-implemented managing system according to claim 43 wherein the sort and query tasks of said task-list means further includes:

(e.2) a second task command for instructing the sort-and-query means to secondly check the differentiable log-out data stored in the first storage means against corresponding ones of the stored exception-definitions on a per-product basis, said checking only covering such second-checked differentiable log-out data belonging to a second predefined time period.

46. A machine-implemented method for reviewing test result data obtained from testing by one or more final wafer sort (FWS) test stations of wafers from one or more production lots, said method comprising the steps of:

(a) obtaining raw test result data from each test station indicating raw test results for a respectively tested wafer;

(b) adding to the raw test result data additional data for distinguishing the obtained raw test result data according to a plurality of sorting criteria, said sorting criteria including time of test and the identity of test equipment participating in the production of the raw test result, said adding step producing differentiable test result data; and

(c) storing the differentiable test result data in a machine-readable storage means.

47. A machine-implemented watchdog system for monitoring the operations of one or more units of final wafer sort (FWS) test equipment, where each unit of FWS test equipment participates as part of one or more FWS test stations in FWS testing of plural dice provided on each of a supplied plurality of wafers from a given production lot of wafers, said FWS testing being for verifying high-level functionality of the tested dice in accordance with one or more predefined test procedures, wherein the tested dice are associated with specific product lines, wherein each FWS test station is operated under supervision of an identifiable operator, and wherein each FWS test station outputs for each wafer tested by said test station, a corresponding block of raw result data indicative of which dice tested as functional or not, said system comprising:

(a) a receiving unit for receiving raw result data from each respective test station the received raw result data indicating FWS test results obtained by the respective test station for a respectively tested wafer; and

(b) a differentiating unit for adding to the received raw result data, additional information signals, said additional information signals enabling the sorting of the raw result data according to one or more predefined sorting criteria;

wherein said predefined sorting criteria include use of one or more of the following sort-keys;

(c.1) the product line of the tested dice;

(c.2) the lot of the tested dice;

(c.3) the operator responsible for supervising the testing of the dice;

(c.4) the time of the testing of the dice; and

(c.5) the test procedure used in the testing of the dice.