System and method for production line monitoring

• US 9,983,148 B2
• Filed: 05/27/2016
• Issued: 05/29/2018
• Est. Priority Date: 05/28/2015
• Status: Active Grant

• Current Assignee: KLA-Tencor Corporation (KLA Corporation)
• Original Assignee: KLA-Tencor Corporation (KLA Corporation)
• Inventors: Paramasivam, Saravanan, Plihal, Martin
• Primary Examiner(s): Nguyen, Sang
• Application Number:
  US15/166,819
• Publication Number:
  US 20160377552A1
• Time in Patent Office: 732 Days
• CPC Class Codes: G01N 2021/8858 Flaw counting
• CPC Class Codes: G01N 21/8851 Scan or image signal processing specially adapted therefor, e.g. for scan signal adjustment, for detecting different kinds of defects, for compensating for structures, markings, edges G01N21/8806 and G01N21/93 - G01N21/95692 take precedence; optical measurement of dimensions G01B11/00; optical scanning G02B26/10; image transformation G06T3/00; computerised image enhancement G06T5/00; image processing per se for flaw detection G06T7/0002
• CPC Class Codes: G01N 21/9501 Semiconductor wafers manufacturing processes per se of semiconductor devices implementing a measuring step H01L22/10
• CPC Class Codes: G05B 19/00 Programme-control systems
• CPC Class Codes: G05B 2219/45031 Manufacturing semiconductor wafers
• CPC Class Codes: G05B 23/0227 Qualitative history assessment, whereby the type of data acted upon, e.g. waveforms, images or patterns, is not relevant, e.g. rule based assessment; if-then decisions
• CPC Class Codes: G05B 23/0275 Fault isolation and identification, e.g. classify fault; estimate cause or root of failure
• CPC Class Codes: H01L 21/67253 Process monitoring, e.g. flow or thickness monitoring
• CPC Class Codes: H01L 22/12 for structural parameters, e.g. thickness, line width, refractive index, temperature, warp, bond strength, defects, optical inspection, electrical measurement of structural dimensions, metallurgic measurement of diffusions electrical measurement of diffusions H01L22/14
• CPC Class Codes: H01L 22/20 Sequence of activities consisting of a plurality of measurements, corrections, marking or sorting steps

Abstract

A method for production line monitoring during semiconductor device fabrication includes acquiring a plurality of inspection results from a plurality of reference samples with an inspection sub-system. The method includes storing the acquired inspection results and geometric pattern codes for each of the reference samples in a database. The method includes acquiring an additional inspection result from an additional sample, where the additional inspection result includes an additional set of geometric pattern codes for identifying each defect identified within the additional inspection result from the additional sample. The method also includes correlating the set of geometric pattern codes of the additional sample with the geometric pattern codes from the reference set of samples to identify at least one of one or more new patterns or one or more patterns displaying a frequency of occurrence above a selected threshold.

Claims

1. A system for semiconductor device production monitoring comprising:

an inspection sub-system including an illumination source and a detector, wherein the illumination source is configured to generate illumination, wherein the inspection sub-system is configured to scan the illumination from the illumination source across a sample, wherein the detector is configured to detect illumination from the sample;

a database maintained in memory for storing inspection results acquired from a reference set of samples with the inspection sub-system, wherein each inspection result from the reference set of samples includes a geometric pattern code for each defect identified on a particular reference sample, wherein the geometric pattern code serves to identify the pattern associated with a particular defect on the particular reference sample; and

an analyzer, the analyzer including one or more processors and memory, wherein the one or more processors are configured to execute a set of program instructions maintained on the memory, the program instructions configured to cause the one or more processors to;

receive an additional inspection result from an additional sample from the inspection sub-system, wherein the additional inspection result includes an additional set of geometric pattern codes for each defect identified within the additional inspection result from the additional sample;

retrieve the inspection results acquired from the reference set of samples including the geometric pattern code for each defect identified on the particular reference sample from the database; and

correlate the set of geometric pattern codes of the additional sample with the geometric pattern codes from the reference set of samples to identify at least one of one or more new patterns or one or more patterns displaying a frequency of occurrence above a selected threshold.

2. The system of claim 1, wherein the correlating the set of geometric pattern codes of the additional sample with the geometric pattern codes from the reference set of samples to identify at least one of one or more new patterns or one or more patterns displaying a frequency of occurrence above a selected threshold comprises:

correlating a frequency of occurrence of each of the set of geometric pattern codes of the additional sample to the frequency of occurrence of each of the set of geometric pattern codes from the reference set of samples to identify at least one of one or more new patterns or one or more patterns displaying a frequency of occurrence above a selected threshold.

3. The system of claim 1, wherein the correlating the set of geometric pattern codes of the additional sample with the geometric pattern codes from the reference set of samples to identify at least one of one or more new patterns or one or more patterns displaying a frequency of occurrence above a selected threshold comprises:

comparing the set of geometric pattern codes of the additional sample to the geometric pattern codes from the reference set of samples to identify a deviation between the set of geometric pattern codes of the additional sample and the geometric pattern codes from the reference set of samples; and

determining whether the deviation is larger than sample-to-sample variations of the geometric pattern codes from the reference set of samples.

4. The system of claim 1, wherein the analyzer is further configured to:

flag at least one of the one or more new patterns or the one or more patterns displaying a frequency of occurrence above a selected threshold.

5. The system of claim 1, wherein the analyzer is further configured to:

report an excursion alert to a user interface in response to the identification of at least one of one or more new patterns or one or more patterns displaying a frequency of occurrence above a selected threshold.

6. The system of claim 1, wherein the analyzer is further configured to:

direct the inspection sub-system to perform one or more inspection measurements on one or more defects associated with at least one of the one or more new patterns or the one or more patterns displaying a frequency of occurrence above a selected threshold.

7. The system of claim 1, wherein the analyzer is further configured to:

provide an identified one or more new patterns to a pattern search database.

8. The system of claim 7, wherein the pattern search database is configured to identify one or more instances of the one or more new patterns in the pattern search data base.

9. The system of claim 8, wherein the pattern search database is configured to transmit the number of instances of the one or more new patterns appearing in the pattern search database to the analyzer.

10. The system of claim 9, wherein the analyzer is configured to correlate the number of instances of the one or more new patterns with a failure frequency of each geometric design code of the reference set of samples and the additional sample stored in the database.

11. The system of claim 10, wherein the analyzer is configured to flag one or more new patterns displaying a failure frequency above a selected threshold as a systematic defect.

12. The system of claim 1, wherein the inspection sub-system is configured in a brightfield inspection mode.

13. The system of claim 1, wherein the inspection sub-system is configured in a darkfield inspection mode.

14. The system of claim 1, wherein the inspection sub-system comprises:

a light-based inspection sub-system.

15. The system of claim 1, wherein the inspection sub-system comprises:

an electron-based inspection sub-system.

16. The system of claim 1, wherein the inspection sub-system comprises:

a narrow band inspection sub-system.

17. The system of claim 1, wherein the inspection sub-system comprises:

a broadband inspection sub-system.

18. The system of claim 17, wherein the broadband inspection sub-system comprises:

a broadband plasma (BPP) inspection sub-system.

19. The system of claim 1, wherein the sample comprises:

a semiconductor wafer.

20. A method for semiconductor device production monitoring comprising:

acquiring, with an illumination source and a detector of an inspection sub-system, a plurality of inspection results from a plurality of reference samples, each inspection result being acquired from one reference sample of the plurality of reference samples, wherein each inspection result includes a geometric pattern code for each defect identified on the particular reference sample, wherein the geometric pattern code serves to identify the pattern associated with the particular defect;

storing the acquired inspection results and the associated geometric pattern codes in a database;

acquiring, with the illumination source and the detector of the inspection sub-system, an additional inspection result from an additional sample, wherein the additional inspection result includes an additional set of geometric pattern codes for identifying each defect identified within the additional inspection result from the additional sample;

correlating, with one or more processors, the set of geometric pattern codes of the additional sample with the geometric pattern codes from the reference set of samples to identify at least one of one or more new patterns or one or more patterns displaying a frequency of occurrence above a selected threshold; and

directing the inspection sub-system to perform one or more inspection measurements on one or more defects associated with at least one of the one or more new patterns or the one or more patterns displaying a frequency of occurrence above a selected threshold.

21. The method of claim 20, wherein the correlating the set of geometric pattern codes of the additional sample with the geometric pattern codes from the reference set of samples to identify at least one of one or more new patterns or one or more patterns displaying a frequency of occurrence above a selected threshold comprises:

correlating a frequency of occurrence of each of the set of geometric pattern codes of the additional sample to the frequency of occurrence of each of the set of geometric pattern codes from the reference set of samples to identify at least one of one or more new patterns or one or more patterns displaying a frequency of occurrence above a selected threshold.

22. The method of claim 20, wherein the correlating the set of geometric pattern codes of the additional sample with the geometric pattern codes from the reference set of samples to identify at least one of one or more new patterns or one or more patterns displaying a frequency of occurrence above a selected threshold comprises:

comparing a frequency of occurrence the set of geometric pattern codes of the additional sample to the geometric pattern codes from the reference set of samples to identify a deviation between the set of geometric pattern codes of the additional sample and the geometric pattern codes from the reference set of samples; and

determining whether the deviation is larger than sample-to-sample variations of the geometric pattern codes from the reference set of samples.

23. The method of claim 20, further comprising:

flagging the one or more patterns displaying at least one of one or more new patterns or one or more patterns displaying a frequency of occurrence above a selected threshold.

24. The method of claim 20, further comprising:

reporting an excursion alert to a user interface in response to at least one of the one or more new patterns or one or more patterns displaying a frequency of occurrence above a selected threshold.

25. The method of claim 20, further comprising:

performing a pattern search on one or more new patterns to identity one or more instances of the one or more new patterns in the database.

26. A system for semiconductor device production monitoring comprising:

an inspection sub-system including an illumination source and a detector, wherein the illumination source is configured to generate illumination, wherein the inspection sub-system is configured to scan the illumination from the illumination source across a sample, wherein the detector is configured to detect illumination from the sample; and

a controller, the controller including one or more processors and memory, wherein the one or more processors are configured to execute a set of program instructions maintained on the memory, the program instructions configured to cause the one or more processors to;

store inspection results acquired from a reference set of samples with the inspection sub-system, wherein each inspection result from the reference set of samples includes a geometric pattern code for each defect identified on a particular reference sample, wherein the geometric pattern code serves to identify the pattern associated with a particular defect on the particular reference sample;

receive an additional inspection result for an additional sample from the inspection sub-system, wherein the additional inspection result includes an additional set of geometric pattern codes for each defect identified within the additional inspection result from the additional sample; and

correlate the set of geometric pattern codes of the additional sample with the geometric pattern codes from the reference set of samples to identify at least one of one or more new patterns or one or more patterns displaying a frequency of occurrence above a selected threshold.