Hierarchical wafer inspection

Patent metadata

Field	Value
Publication number	US-10732128-B2
Application number	US-201816162539-A
Country	US
Kind code	B2
Filing date	Oct 17, 2018
Priority date	Oct 26, 2017
Publication date	Aug 4, 2020
Grant date	Aug 4, 2020

Abstract

There may be provided a method for evaluating an object, that may include evaluating a region of the object by a first evaluation module to provide first evaluation results that are related to multiple sites of the region; finding, using a mapping between values of first evaluation results and values of second evaluation results, (a) a first site of the multiple sites that does not require an evaluation by a second evaluation module, and (b) a second site of the multiple sites that requires an evaluation by the second evaluation module; wherein the second evaluation module is more reliable than the first evaluation module; evaluating the second site by the second evaluation module to provide second evaluation results of the second sites; estimating, based on first evaluation results of the first site and on the mapping, a state of the first site; and providing an evaluation of the region based on the state of the first site, and on the second evaluation result of the second site.

First claim

We claim:

1. A method for evaluating an object, the method comprises:
evaluating a region of the object by a first evaluation module to provide first evaluation results that are related to multiple sites of the region;
finding, using a mapping between values of first evaluation results and values of second evaluation results, (a) a first site of the multiple sites that does not require an evaluation by a second evaluation module, and (b) a second site of the multiple sites that requires an evaluation by the second evaluation module; wherein the second evaluation module is more reliable than the first evaluation module;
evaluating the second site by the second evaluation module, while not evaluating the first site by the second evaluation module, to provide second evaluation results of the second sites;
wherein the values of the first evaluation results are classified to a class out of (a) an indefinite class that requires the evaluation by the second evaluation module, and (b) at least one definitive class that does not require the evaluation by the second evaluation module;
estimating, based on first evaluation results of the first site and on the mapping, a state of the first site; and
providing an evaluation of the region based on the state of the first site, and on the second evaluation result of the second site.

2. The method according to claim 1 wherein the values of the second results are classified to a indefinite class that require the evaluation by the second evaluation module, and at least one definitive class that does not require the evaluation by the second evaluation module.

3. The method according to claim 1 comprising finding the first site when a first evaluation result related to the first site is mapped to a second evaluation result value that belongs to the at least one definitive class; and finding the second site when a first evaluation result related to the second site is mapped to a second evaluation result value that belongs to the indefinite class.

4. The method according to claim 1 wherein the at least one definitive class comprises a faulty class and an proper class; wherein values of the second results that belong to the faulty class are indicative of a faulty site; and wherein values of the second results that belong to the proper class are indicative of a proper site.

5. The method according to claim 4 comprising estimating the state of the first site as proper when a first evaluation result related to the first site is mapped to a second evaluation result value that belongs to the proper class; and estimating the state of the first site as faulty when a first evaluation result related to the first site is mapped to a second evaluation result value that belongs to the faulty class.

6. The method according to claim 1 comprising changing a boundary of at least one class over time.

7. The method according to claim 1 comprising defining the indefinite class based on a timing constraint imposed on the evaluation of the region.

8. The method according to claim 1 wherein the first evaluation module is an inspection unit and the second evaluation is an analysis unit.

9. The method according to claim 1 wherein the first evaluation module is an inspection unit and the second evaluation is a metrology unit.

10. The method according to claim 1 wherein the first evaluation module differs from the second evaluation by a frequency of radiation that irradiates the object.

11. A non-transitory computer readable medium for evaluating an object, that stores instructions for:
evaluating a region of the object by a first evaluation module to provide first evaluation results that are related to multiple sites of the region;
finding, using a mapping between values of first evaluation results and values of second evaluation results, (a) a first site of the multiple sites that does not require an evaluation by a second evaluation module, and (b) a second site of the multiple sites that requires an evaluation by the second evaluation module; wherein the second evaluation module is more reliable than the first evaluation module;
evaluating the second site by the second evaluation module while not evaluating the first site by the second evaluation module, to provide second evaluation results of the second sites;
wherein the values of the first evaluation results are classified to a class out of (a) an indefinite class that requires the evaluation by the second evaluation module, and (b) at least one definitive class that does not require the evaluation by the second evaluation module;
estimating, based on first evaluation results of the first site and on the mapping, a state of the first site; and
providing an evaluation of the region based on the state of the first site, and on the second evaluation result of the second site.

12. The non-transitory computer readable medium according to claim 11 wherein the values of the second results are classified to a indefinite class that require the evaluation by the second evaluation module, and at least one definitive class that does not require the evaluation by the second evaluation module.

13. The non-transitory computer readable medium according to claim 11 that stores instructions for finding the first site when a first evaluation result related to the first site is mapped to a second evaluation result value that belongs to the at least one definitive class; and finding the second site when a first evaluation result related to the second site is mapped to a second evaluation result value that belongs to the indefinite class.

14. The non-transitory computer readable medium according to claim 11 wherein the at least one definitive class comprises a faulty class and an proper class; wherein values of the second results that belong to the faulty class are indicative of a faulty site; and wherein values of the second results that belong to the proper class are indicative of a proper site.

15. The non-transitory computer readable medium according to claim 14 that stores instructions for estimating the state of the first site as proper when a first evaluation result related to the first site is mapped to a second evaluation result value that belongs to the proper class; and estimating the state of the first site as faulty when a first evaluation result related to the first site is mapped to a second evaluation result value that belongs to the faulty class.

16. The non-transitory computer readable medium according to claim 11 that stores instructions for changing a boundary of at least one class over time.

17. The non-transitory computer readable medium according to claim 11 that stores instructions for defining the indefinite class based on a timing constraint imposed on the evaluation of the region.

18. The non-transitory computer readable medium according to claim 11 wherein the first evaluation module is an inspection unit and the second evaluation is an analysis unit.

19. The non-transitory computer readable medium according to claim 11 wherein the first evaluation module is an inspection unit and the second evaluation is a metrology unit.

20. The non-transitory computer readable medium according to claim 11 wherein the first evaluation module differs from the second evaluation by a frequency of radiation that irradiates the object.

21. A system for evaluating an object, the system comprising a first evaluation module, a processor, and a second evaluation module;
wherein the first evaluation module is configured to evaluate a region

Assignees

• Camtek Ltd

Inventors

• Regensburger Menachem

Classifications

• H10P74/203

  Structural properties, e.g. testing or measuring thicknesses, line widths, warpage, bond strengths or physical defects · CPC title

• H10P74/23 Primary

  characterised by multiple measurements, corrections, marking or sorting processes · CPC title

• G01N21/8806

  Specially adapted optical and illumination features · CPC title

• G01N21/9505 Primary

  Wafer internal defects, e.g. microcracks · CPC title

• H01L22/20

  Electricity · mapped topic