Management system, apparatus, and method, exposure apparatus, and control method therefor

• US 20030202182A1
• Filed: 04/28/2003
• Published: 10/30/2003
• Est. Priority Date: 04/30/2002
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Oishi, Satoru, Ina, Hideki, Sentoku, Koichi, Suzuki, Takehiko, Matsumoto, Takahiro
• Granted Patent: US 6,992,767 B2
• Time in Patent Office: Days
• US Class Current: 356/401
• CPC Class Codes: G03F 7/70633 Overlay, i.e. relative alignment between patterns printed by separate exposures in different layers, or in the same layer in multiple exposures or stitching
• CPC Class Codes: G03F 9/7092 Signal processing

Abstract

An exposure apparatus performs AGA measurement by using a predetermined sample shot group formed on a wafer, and decides an alignment parameter. The exposure apparatus executes wafer alignment processing and exposure processing by using the alignment parameter. The exposure apparatus notifies a central processing unit (4) of AGA measurement results and the alignment parameter. An overlay inspection apparatus measures an actual exposure position on the exposed wafer, and notifies the central processing unit of the measurement result. The central processing unit (4) optimizes alignment processing on the basis of the AGA measurement results, alignment parameter, and actually measured exposure position.

Claims

1. A management system which manages alignment processing of an exposure apparatus, comprising:

measurement means for measuring a position of a mark position on a photosensitive substrate;

exposure processing means for calculating an alignment parameter on the basis of a measurement result of said measurement means, executing alignment processing by using the calculated alignment parameter, and exposing the photosensitive substrate;

an inspection apparatus which measures an exposure position on the photosensitive substrate exposed by said exposure processing means; and

optimization means for optimizing the alignment processing on the basis of the exposure position acquired by said inspection apparatus.

2. The system according to claim 1, wherein said optimization means comprises update means for updating an offset amount of the alignment parameter used in the alignment processing.

3. The system according to claim 2, wherein said update means acquires, from the exposure position measured by said inspection apparatus, a shift amount between a measurement position by said measurement means and the exposure position, and updates the offset amount on the basis of the shift amount.

4. The system according to claim 3, wherein the offset amount includes a mean value of shift amounts acquired for a plurality of photosensitive substrates.

5. The system according to claim 2, wherein

said measurement means measures positions of marks in a plurality of shot regions on the photosensitive substrate, and

said update means updates the offset amount for each of the plurality of shot regions.

6. The system according to claim 5, wherein the plurality of shot regions include a sample shot region group and an alternative shot region group used in the alignment processing.

7. The system according to claim 1, wherein

said measurement means measures alignment marks in a plurality of sample shot regions on the photosensitive substrate, and

said optimization means comprises update means for estimating, on the basis of the exposure position measured by said inspection apparatus and a measurement position obtained by said measurement means, exposure results of performing exposure processing in different combinations of sample shot regions, and updating a combination of sample shot regions on the basis of an estimation result.

8. The system according to claim 7, wherein said update means obtains variations in magnification error on the basis of the estimation result, and selects a combination of sample shot regions so as to minimize the variations in magnification error.

9. The system according to claim 7, wherein said update means obtains variations in orthogonality error on the basis of the estimation result, and selects a combination of sample shot regions so as to minimize the variations in orthogonality error.

10. The system according to claim 7, wherein said update means obtains alignment error components of all shots on the basis of the estimation result, and selects a combination of sample shot regions so as to minimize the alignment error components.

11. The system according to claim 7, wherein when the combination of sample shot regions designates setting of a sample shot region group to be used in the alignment processing for each divided region on the photosensitive substrate, said update means estimates an exposure result of performing exposure processing by using a sample shot group set for each divided region.

12. A management method of managing alignment processing of an exposure apparatus, comprising:

a measurement step of measuring a position of a mark on a photosensitive substrate;

an exposure processing step of calculating an alignment parameter on the basis of a measurement result in the measurement step, executing alignment processing by using the calculated alignment parameter, and exposing the photosensitive substrate;

an inspection step of inspecting an exposure result in the exposure processing step; and

an optimization step of optimizing the alignment processing on the basis of an exposure position acquired in the inspection step.

13. The method according to claim 12, wherein the optimization step comprises an update step of updating an offset amount of the alignment parameter used in the alignment processing.

14. The method according to claim 13, wherein in the update step, a shift amount between a measurement position in the measurement step and the exposure position is acquired from the exposure position measured in the inspection step, and the offset amount is updated on the basis of the shift amount.

15. The method according to claim 14, wherein the offset amount includes a mean value of shift amounts acquired for a plurality of photosensitive substrates.

16. The method according to claim 13, wherein

in the measurement step, positions of marks in a plurality of shot regions on the photosensitive substrate are measured, and

in the update step, the offset amount is updated for each of the plurality of shot regions.

17. The method according to claim 16, wherein the plurality of shot regions include a sample shot region group and an alternative shot region group used in the alignment processing.

18. The method according to claim 12, wherein

in the measurement step, positions of marks in a plurality of sample shot regions on the photosensitive substrate are measured, and

the optimization step comprises an update step of estimating, on the basis of the exposure position measured in the inspection step and a measurement position obtained in the measurement step, exposure results of performing exposure processing in different combinations of sample shot regions, and updating a combination of sample shot regions on the basis of an estimation result.

19. The method according to claim 18, wherein in the update step, variations in magnification error are obtained on the basis of the estimation result, and a combination of sample shot regions is so selected as to minimize the variations in magnification error.

20. The method according to claim 18, wherein in the update step, variations in orthogonality error are obtained on the basis of the estimation result, and a combination of sample shot regions is so selected as to minimize the variations in orthogonality error.

21. The method according to claim 18, wherein in the update step, alignment error components of all shots are obtained on the basis of the estimation result, and a combination of sample shot regions is so selected as to minimize the alignment error components.

22. The method according to claim 18, wherein in the update step, when the combination of sample shot regions designates setting of a sample shot region group to be used in the alignment processing for each divided region on the photosensitive substrate, an exposure result of performing exposure processing by using a sample shot group set for each divided region is estimated.

23. A management apparatus which manages alignment processing of an exposure apparatus, comprising:

first acquisition means for acquiring a measurement result of a position of a mark on a photosensitive substrate by the exposure apparatus;

second acquisition means for acquiring an actual exposure position by an inspection apparatus which inspects an exposure result by the exposure apparatus; and

optimization means for optimizing the alignment processing in the exposure apparatus on the basis of the measurement result acquired by said first acquisition means and the exposure position acquired by said second acquisition means.

24. The apparatus according to claim 23, wherein said optimization means comprises update means for updating an offset amount of an alignment parameter used in the alignment processing.

25. The apparatus according to claim 23, wherein

said measurement means measures positions of marks in a plurality of sample shot regions on the photosensitive substrate, and

said optimization means comprises update means for estimating, on the basis of the exposure position acquired by said second acquisition means and the measurement position acquired by said first acquisition means, exposure results of performing exposure processing in different combinations of sample shot regions, and updating a combination of sample shot regions on the basis of an estimation result.

26. A management method of managing alignment processing of an exposure apparatus, comprising:

a first acquisition step of acquiring a measurement result of a position of a mark on a photosensitive substrate by the exposure apparatus;

a second acquisition step of acquiring an actual exposure position by an inspection apparatus which inspects an exposure result by the exposure apparatus; and

an optimization step of optimizing the alignment processing in the exposure apparatus on the basis of the measurement result acquired in the first acquisition step and the exposure position acquired in the second acquisition step.

27. The method according to claim 26, wherein the optimization step comprises an update step of updating an offset amount of an alignment parameter used in the alignment processing.

28. The method according to claim 26, wherein

in the measurement step, positions of marks in a plurality of sample shot regions on the photosensitive substrate are measured, and

the optimization step comprises an update step of estimating, on the basis of the exposure position acquired in the second acquisition step and the measurement position acquired in the first acquisition step, exposure results of performing exposure processing in different combinations of sample shot regions, and updating a combination of sample shot regions on the basis of an estimation result.

29. A computer-readable memory which stores a control program for causing a computer to execute a method defined in claim 26.