Method for calibrating optical-based metrology tools

• US 6,623,994 B1
• Filed: 09/26/2002
• Issued: 09/23/2003
• Est. Priority Date: 09/26/2002
• Status: Active Grant

• Current Assignee: Globalfoundries US Incorporated (GlobalFoundries, Inc.)
• Original Assignee: Advanced Micro Devices, Inc.
• Inventors: Stirton, James Broc
• Primary Examiner(s): Niebling, John F.
• Assistant Examiner(s): LUK, OLIVIA T
• Application Number:
  US10/255,509
• Time in Patent Office: 362 Days
• Field of Search: 438/14-16, 438/5-13, 438/17-18, 716/4, 118/679
• US Class Current: 438/14
• CPC Class Codes: G01B 11/00 Measuring arrangements characterised by the use of optical techniques
• CPC Class Codes: G01N 21/274 Calibration, base line adjustment, drift correction

Abstract

The present invention is generally directed to various methods for calibrating optical-based metrology tools. In one illustrative embodiment, the method comprises performing a metrology process on a specimen using an optical-based metrology tool to obtain optical characteristic data and comparing the obtained optical characteristic data to target optical characteristic data established for the specimen.

Claims

1. A method of qualifying an optical-based metrology tool, comprising:

performing a metrology process on a specimen using said optical-based metrology tool to obtain optical characteristic data;

comparing aid obtained optical characteristic data to target optical characteristic data established for said specimen; and

initiating a maintenance procedure on said optical-based metrology tool based upon a variance between said obtained optical characteristic data and said target optical characteristic data.

2. The method of claim 1, wherein said optical-based metrology tool is comprised of at least one of a reflectometer, an ellipsometer, a spectroscopic ellipsometer and a scatterometer.

3. The method of claim 1, wherein said specimen is comprised of a semiconducting substrate.

4. The method of claim 1, wherein said specimen comprises a semiconducting substrate and wherein said obtained optical characteristic data is directed to at least one of a size of a feature formed above said substrate, a width of a line, a width of a trench, a thickness of at least one layer of material, a cross-sectional profile of a feature, and a dispersion coefficient.

5. The method of claim 1, further comprising determining if a variance exists between said obtained optical characteristic data and said target optical characteristic data.

6. The method of claim 1, further comprising determining if a variance between said obtained optical characteristic data and said target optical characteristic data is less than a preselected value.

7. The method of claim 1, further comprising determining if a variance between said obtained optical characteristic data and said target optical characteristic data is greater than a preselected value.

8. The method of claim 1, further comprising determining if a variance between said obtained optical characteristic data and said target optical characteristic data is within preselected allowable limits.

9. The method of claim 1, further comprising limiting use of said optical-based metrology tool based upon a variance between said obtained optical characteristic data and said target optical characteristic data.

10. A method of qualifying an optical-based metrology tool, comprising:

performing a metrology process on a specimen using said optical-based metrology tool to obtain optical characteristic data;

comparing said obtained optical characteristic data to target optical characteristic data established for said specimen;

determining if a variance exists between said obtained optical characteristic data and said target optical characteristic data; and

removing said optical-based metrology tool from service based upon the existence of a determined variance between said obtained optical characteristic data and said target optical characteristic data.

11. The method of claim 10, wherein said optical-based metrology tool is comprised of at least one of a reflectometer, an ellipsometer, a spectroscopic ellipsometer and a scatterometer.

12. The method of claim 10, wherein said specimen comprises a semiconducting substrate and wherein said obtained optical characteristic data is directed to at least one of a size of a feature formed above said substrate, a width of a line, a width of a trench, a thickness of at least one layer of material, a cross-sectional profile of a feature, and a dispersion coefficient.

13. The method of claim 10, wherein determining if said variance exists between the obtained optical characteristic data and the target optical characteristic data further comprises determining if a variance between said obtained optical characteristic data and said target optical characteristic data is less than a preselected value.

14. The method of claim 10, wherein determining if said variance exists between the obtained optical characteristic data and the target optical characteristic data further comprises determining if a variance between said obtained optical characteristic data and said target optical characteristic data is greater than a preselected value.

15. The method of claim 10, wherein determining if said variance exists between the obtained optical characteristic data and the target optical characteristic data further comprises determining if a variance between said obtained optical characteristic data and said target optical characteristic data is within preselected allowable limits.

16. A method of qualifying an optical-based metrology tool, comprising:

performing a metrology process on a specimen using said optical-based metrology tool to obtain optical characteristic data;

comparing said obtained optical characteristic data to target optical characteristic data established for said specimen; and

removing said optical-based metrology tool from service if a variance between said obtained optical characteristic data and said target optical characteristic data exceeds a preselected limit.

17. The method of claim 16, wherein said optical-based metrology tool is comprised of at least one of a reflectometer, an ellipsometer, a spectroscopic ellipsometer and a scatterometer.

18. The method of claim 16, wherein said specimen is comprised of a semiconducting substrate.

19. The method of claim 16, wherein said specimen comprises a semiconducting substrate and wherein said obtained optical characteristic data is directed to at least one of a size of a feature formed above said substrate, a width of a line, a width of a trench, a thickness of at least one layer of material, a cross-sectional profile of a feature, and a dispersion coefficient.

20. The method of claim 16, wherein removing said optical-based metrology tool from service comprises limiting use of said optical-based metrology tool based upon said variance between said obtained optical characteristic data and said target optical characteristic data.

21. The method of claim 16, further comprising initiating a maintenance procedure on said optical-based metrology tool based upon said variance between said obtained optical characteristic data and said target optical characteristic data.

22. A method of qualifying an optical-based metrology tool, comprising:

performing a metrology process on a specimen using said optical-based metrology tool to obtain optical characteristic data;

comparing said obtained optical characteristic data to target optical characteristic data established for said specimen; and

limiting use of said optical-based metrology tool to specific metrology applications based upon a variance between said obtained optical characteristic data and said target optical characteristic data.

23. The method of claim 22, wherein said optical-based metrology tool is comprised of at least one of a reflectometer, an ellipsometer, a spectroscopic ellipsometer and a scatterometer.

24. The method of claim 22, wherein said specimen is comprised of a semiconducting substrate.

25. The method of claim 22, wherein said specimen comprises a semiconducting substrate and wherein said obtained optical characteristic data is directed to at least one of a size of a feature formed above said substrate, a width of a line, a width of a trench, a thickness of at least one layer of material, a cross-sectional profile of a feature, and a dispersion coefficient.

26. The method of claim 22, further comprising initiating a maintenance procedure on said optical-based metrology tool based upon said variance between said obtained optical characteristic data and said target optical characteristic data.