Dynamic creation and modification of wafer test maps during wafer testing

• US 20060064268A1
• Filed: 11/03/2005
• Published: 03/23/2006
• Est. Priority Date: 04/17/2003
• Status: Abandoned Application

• Current Assignee: Micron Technology, Inc.
• Original Assignee: Micron Technology, Inc.
• Inventors: Velichko, Sergey A., Dorough, Michael J., Gravelle, Robert M.
• Application Number:
  US11/265,897
• Publication Number:
  US 20060064268A1
• Time in Patent Office: Days
• US Class Current: 702/117
• 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 31/2894 Aspects of quality control [QC] G01R31/31718 takes precedence; program control for QC G05B19/41875

Abstract

Methods, systems, and apparatuses provide dynamic creation and modification of wafer test maps. Test plans are defined for a testing session of a wafer lot. The test plan is associated with a number of seed map patterns. During a wafer lot testing session, test results are dynamically obtained and examined at run-time of a test. Moreover, the seed map patterns are overlaid on the test sites defined in the test plan. If the test result statistics are outside of defined threshold tolerance levels, then a new wafer test map is created or modified at run-time, according to corresponding seed map patterns. If seed map patterns are within the intersection of valid test sites, then seed map patterns are created at run-time.

Claims

1. A dynamic wafer testing system, comprising:

a data store of patterns associated with testing maps; and

a test station controller that dynamically creates one or more of the testing maps associated with a number of the patterns that are detected on sites to be tested on a lot of wafers, and wherein the test station controller can process a number of the dynamically created one or more testing maps in parallel.

3. The dynamic wafer testing system of claim 1, wherein the wafer test station controller dynamically creates one or more of the testing maps by overlaying a number of the patterns acquired from the data store onto the sites identified for testing on the lot of wafers.

4. The dynamic wafer testing system of claim 1, wherein if one of the testing maps tests one of the sites for one of the wafers in the lot, then the remaining testing maps do not retest the previously tested site for any of the remaining wafers being tested in the lot.

5. The dynamic wafer testing system of claim 1, wherein a number of registers to test the wafers are identified in a test plan, and the registers include active sensors, and a number of testing maps that are created are limited by a configurable allocated production time and the registers with active sensors.

6. The dynamic wafer testing system of claim 1, wherein the sites are used to form a default testing map for the wafers in the lot.

2. The dynamic wafer testing system 1, wherein the wafer test station controller dynamically creates one or more of the testing maps based on test results associated with testing another one of the testing maps.

7. A data store implemented in a machine-accessible medium, the data store used for assembling test maps, wherein the test maps are processed by a machine, the data store comprising:

parameters associated with wafer test plans, wherein a particular one of the parameters identifies a particular one of the wafer test plans; and

seeds associated with geometric shapes identified on wafers, wherein the seeds are sensitive to and include previously identified failing site locations on the wafers and failing site locations'"'"' symptoms, wherein the data store is to be accessed to selectively acquire one or more of the wafer test plans and to selectively acquire one or more of the seeds for dynamically assembling and processing tests on the wafers.

8. The data store of claim 7, wherein the parameters further include types of data and/or statistics to be collected when the wafer test plans are processed on the wafers.

9. The data store of claim 8, wherein the types of the data and/or statistics collected are to be stored in a parameter data store by the machine that processes the tests.

10. The data store of claim 7, wherein the wafer test plans identify sites on the wafers to test and to identify test operations to be performed as a number of the tests on the wafers.

11. The data store of claim 7, wherein the seeds are associated with specific test registers of the machine.

12. The data store of claim 7, wherein the seeds are associated with seed maps that include at least one of a Single-Site seed map, a Center-To-Edge seed map, an Edge-Only seed map, a Center-Only seed map, and a Notch-Only seed map.

13. A data store implemented in a machine-accessible medium, the data store used for housing results associated with processing dynamically created wafer test maps, the data store comprising:

wafer identifiers associated with wafers;

test identifiers associated with tests; and

results associated with select ones of the wafer identifiers and associated with select ones of the test identifiers in response to processing select ones of the tests on select ones of the wafers.

14. The data store of claim 13, wherein data types collected in the results are pre-defined and acquired from a different data store in response to the test identifiers.

15. The data store of claim 13 further comprising, statistics associated with select ones of the wafer identifiers and associated with select ones of the test identifiers in response to processing select ones of the tests on select ones of the wafers.

16. The data store of claim 13, wherein the results are to be populated with appropriate ones of the test identifiers and the wafers by a controller that processes the tests by updating the data store.

17. A data structure implemented in a machine-accessible medium, the data structure representing a dynamically created and populated wafer test map pattern, the locations of the wafer test map pattern are associated with a wafer and at those locations within the wafer a machine processes tests, the data structure comprising:

a wafer die for a given wafer; and

a pattern within the wafer die, wherein the pattern is to be dynamically defined overlaying one or more shape templates on top of available test sites for the wafer die, and wherein the pattern represents a geometric pattern of locations within the wafer die where tests are to be performed.

18. The data structure of claim 17, wherein the pattern excludes a number of the locations that are associated with any previously processed tests which were processed against the wafer die using an initial test map.

19. The data structure of claim 17, wherein the shape templates are to be selectively acquired by a controller from a data store before the controller dynamically generates and populates the data structure.

20. The data structure of claim 17, wherein the shape templates are represented in a formal mathematical representation and are processed to generate different patterns that are overlaid on the available test sites.

21. A data structure implemented in a machine-accessible medium, the data structure defines a shape template for use in dynamically creating a wafer test map pattern, the test map pattern used to process tests on a wafer at defined locations associated with the pattern, and the data structure comprising:

coordinates to define a center of a wafer die;

a first set of sites to include within the wafer die relative to the center; and

a second set of sites to exclude within the wafer die relative to the center;

wherein the first and second sets represents locations identified for testing and locations identified for no testing within the wafer die as defined by the data structure, and wherein the locations identified for testing produce a geometric pattern or shape.

22. The data structure of claim 21, wherein the first set is represented in formal mathematical notation within the data structure that when processed produces the geometric pattern or the shape.

23. The data structure of claim 22, wherein the formal mathematical notation is a definition of a function, and wherein the function is at least one of quadratic and non quadratic.

24. The method of claim 21, wherein multiple instances of the data structure are indexed and housed in a data store.

25. A system, comprising:

a testing data store to house one or more testing maps and one or more shape templates; and

a results data store to house results data produced by processing tests;

wherein a controller is to dynamically access the testing data store to selectively acquire one of the testing maps and one of the shape templates, and wherein the controller is to dynamically create a dynamic testing pattern on a wafer by overlaying the selected shape template and the selected testing map on the wafer to acquire the testing pattern, and the controller is to dynamically process select ones of the tests on locations of the wafer that are included within the testing pattern.

26. The system of claim 25, wherein the testing data store further includes types of data and types of statistics to represents the results data, which the controller updates to the results data store in response to processing the select ones of the tests.

27. The system of claim 25, wherein the selected shape template represents pre-identified problem areas within the wafer that are know to exist from previous tests processed against the wafer.

28. A system, comprising:

a test map;

a seed data structure; and

a new test map, wherein the test map is to define available locations within a wafer die for testing, the seed data structure is to define pre-defined problems within the wafer die at select ones of the available locations, and wherein the new test map is to be dynamically created by overlaying the seed data structure and the test map on the wafer die and excluding a number of the available locations where tests have already been processed and including remaining locations associated with the seed data structure.

29. The system of claim 28, wherein the seed data structure is represented in formal notation to generate a pattern, the pattern when overlaid on the wafer die identifies the select locations within the wafer die.

30. The system of claim 28 further comprising, a results data store to house results of tests processed using the new test map.