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

• US 7,385,700 B2
• Filed: 09/06/2005
• Issued: 06/10/2008
• Est. Priority Date: 04/30/2002
• Status: Expired due to Fees

• 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
• Primary Examiner(s): Lauchman; Layla G.
• Application Number:
  US11/218,538
• Publication Number:
  US 20060050274A1
• Time in Patent Office: 1,008 Days
• Field of Search: 356399-401, 355/53, 355/55, 355/67, 700/28, 700/29, 250/548, 250/492.2
• 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 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 optimizes alignment processing on the basis of the AGA measurement results, alignment parameter, and actually measured exposure position.

Claims

1. A processing method for obtaining a condition of an alignment measurement by an exposure apparatus for exposing a substrate to light, said method comprising steps of:

acquiring first data of a difference between a calculated position of an alignment mark of a sampled area on the substrate calculated based on a plurality of measured positions of a plurality of alignment marks of a plurality of sampled areas on the substrate and a measured position of the alignment mark with respect to each of the plurality of sampled areas, the difference being obtained by the exposure apparatus;

acquiring second data of an overlay error of a pattern on the substrate with respect to each of the plurality of sampled areas, the pattern being formed by exposing the substrate to the light based on the calculated positions of the plurality of alignment marks by the exposure apparatus, the overlay error being obtained by an overlay inspection apparatus;

a first calculation of calculating a measurement error of the measured position based on the first and second data with respect to each of the plurality of sampled areas; and

a second calculation of calculating an offset to be used for the measured position as the condition of the alignment measurement based on a plurality of measurement errors obtained over a plurality of substrates through said first calculation step with respect to each of the plurality of sampled areas.

2. A method according to claim 1, wherein said first calculation step calculates the measurement error by adding the first and second data.

3. A method according to claim 1, wherein said second calculation step calculates the offset by averaging the plurality of measurement errors over the plurality of substrates.

4. A method of manufacturing a device, comprising steps of:

exposing a substrate to light using an exposure apparatus of which a condition of an alignment measurement is obtained through a processing method as defined in claim 1;

developing the exposed substrate; and

processing the developed substrate to manufacture the device.

5. A processing method for obtaining a condition of an alignment measurement by an exposure apparatus for exposing a substrate to light, said method comprising steps of:

acquiring first data of a difference between a calculated position of an alignment mark of a sampled area on the substrate calculated based on a plurality of measured positions of a plurality of alignment marks of a plurality of sampled areas on the substrate and the measured position of the alignment mark with respect to each of the plurality of sampled areas, the difference being obtained by the exposure apparatus;

acquiring second data of an overlay error of a pattern on the substrate with respect to each of the plurality of sampled areas, the pattern being formed by exposing the substrate to the light based on the calculated positions of the plurality of alignment marks by the exposure apparatus, the overlay error being obtained by an overlay inspection apparatus;

estimating an alignment error to be obtained with respect to each of a plurality of subsets of the plurality of sampled areas based on the first and second data; and

selecting, as the condition of the alignment measurement, a subset to be used for the alignment measurement from the plurality of subsets based on a plurality of alignment errors estimated in said estimating step.

6. A method according to claim 5, wherein said estimating step calculates a coefficient for approximately obtaining the measured position of the alignment mark from a position designed for the alignment mark based on the first data with respect to each of the plurality of subsets, and estimates the alignment error based on the coefficient and the second data with respect to each of the plurality of subsets.

7. A method according to claim 5, wherein said selecting step calculates a standard deviation of the plurality of estimated alignment errors with respect to each of the plurality of subsets, and selects the subset to be used for the alignment measurement based on a plurality of calculated standard deviations.

8. A method of manufacturing a device, comprising steps of:

exposing a substrate to light using an exposure apparatus of which a condition of an alignment measurement is obtained through a processing method as defined in claim 5;

developing the exposed substrate; and

processing the developed substrate to manufacture the device.

9. A processing apparatus for obtaining a condition of an alignment measurement by an exposure apparatus for exposing a substrate to light, said apparatus comprising:

a storage configured to store first data of a difference between a calculated position of an alignment mark of a sampled area on the substrate calculated based on a plurality of measured positions of a plurality of the alignment marks of a plurality of the sampled areas on the substrate and the measured position of the alignment mark with respect to each of the plurality of sampled areas, the difference being obtained by the exposure apparatus, and to store second data of an overlay error of a pattern on the substrate with respect to each of the plurality of sampled areas, the pattern being formed by exposing the substrate to the light based on the calculated positions of the plurality of alignment marks by the exposure apparatus, the overlay error being obtained by an overlay inspection apparatus; and

a processor configured to calculate a measurement error of the measured position based on the first and second data with respect to each of the plurality of sampled areas, and to calculate an offset to be used for the measured position as the condition of the alignment measurement based on a plurality of calculated measurement errors obtained over a plurality of substrates with respect to each of the plurality of sampled areas.

10. An apparatus according to claim 9, wherein said processor is configured to calculate the measurement error by adding the first and second data.

11. An apparatus according to claim 9, wherein said processor is configured to calculate the offset by averaging the plurality of measurement errors over the plurality of substrates.

12. A processing apparatus for obtaining a condition of an alignment measurement by an exposure apparatus for exposing a substrate to light, said apparatus comprising:

a storage configured to store first data of a difference between a calculated position of an alignment mark of a sampled area on the substrate calculated based on a plurality of measured positions of a plurality of alignment marks of a plurality of sampled areas on the substrate and the measured position of the alignment mark with respect to each of the plurality of sampled areas, the difference being obtained by the exposure apparatus, and to store second data of an overlay error of a pattern on the substrate with respect to each of the plurality of sampled areas, the pattern being formed by exposing the substrate to the light based on the calculated positions of the plurality of alignment marks by the exposure apparatus, the overlay error being obtained by an overlay inspection apparatus; and

a processor configured to estimate an alignment error to be obtained with respect to each of a plurality of subsets of the plurality of sampled areas based on the first and second data, and to select, as the condition of the alignment measurement, a subset to be used for the alignment measurement from the plurality of subsets based on the estimated alignment errors.

13. An apparatus according to claim 12, wherein said processor is configured to calculate a coefficient for approximately obtaining the measured position of the alignment mark from a position designed for the alignment mark based on the first data with respect to each of the plurality of subsets, and to estimate the alignment error based on the coefficient and the second data with respect to each of the plurality of subsets.

14. An apparatus according to claim 12, wherein said processor is configured to calculate a standard deviation of the estimated alignment errors with respect to each of the plurality of subsets, and to select the subset to be used for the alignment measurement based on the calculated standard deviations.

15. A program for causing a computer to execute a processing method for obtaining a condition of an alignment measurement by an exposure apparatus for exposing a substrate to light, said method comprising steps of:

acquiring first data of a difference between a calculated position of an alignment mark of a sampled area on the substrate calculated based on a plurality of measured positions of a plurality of alignment marks of a plurality of the sampled areas on the substrate and the measured position of the alignment mark with respect to each of the plurality of sampled areas, the difference being obtained by the exposure apparatus;

acquiring second data of an overlay error of a pattern on the substrate with respect to each of the plurality of sampled areas, the pattern formed by exposing the substrate to the light based on the calculated positions of the plurality of alignment marks by the exposure apparatus, the overlay error being obtained by an overlay inspection apparatus;

a first calculation of calculating a measurement error of the measured position based on the first and second data with respect to each of the plurality of sampled areas; and

a second calculation of calculating an offset to be used for the measured position as the condition of the alignment measurement based on a plurality of measurement errors obtained over a plurality of substrates through said first calculation step with respect to each of the plurality of sampled areas.

16. A program for causing a computer to execute a processing method for obtaining a condition of an alignment measurement by an exposure apparatus for exposing a substrate to light, said method comprising steps of:

acquiring first data of a difference between a calculated position of an alignment mark of a sampled area on the substrate calculated based on a plurality of measured positions of a plurality of alignment marks of a plurality of sampled areas on the substrate and the measured position of the alignment mark with respect to each of the plurality of sampled areas, the difference being obtained by the exposure apparatus;

acquiring second data of an overlay error of a pattern on the substrate with respect to each of the plurality of sampled areas, the pattern being formed by exposing the substrate to the light based on the calculated positions of the plurality of alignment marks by the exposure apparatus, the overlay error being obtained by an overlay inspection apparatus;

estimating an alignment error to be obtained with respect to each of a plurality of subsets of the plurality of sampled areas based on the first and second data; and

selecting, as the condition of the alignment measurement, a subset to be used for the alignment measurement from the plurality of subsets based on a plurality of alignment errors estimated in said estimating step.

17. A processing method for obtaining a condition of an alignment measurement by an exposure apparatus for exposing a substrate to light, said method comprising steps of:

acquiring first data of a difference between a calculated position of an alignment mark of a sampled area on the substrate calculated based on a plurality of measured positions of a plurality of alignment marks of a plurality of sampled areas on the substrate and the measured position of the alignment mark with respect to each of the plurality of sampled areas, the difference being obtained by the exposure apparatus;

acquiring second data of an overlay error of a pattern on the substrate with respect to each of the plurality of sampled areas, the pattern being formed by exposing the substrate to the light based on the calculated positions of the plurality of alignment marks by the exposure apparatus, the overlay error being obtained by an overlay inspection apparatus; and

obtaining the condition of the alignment measurement based on the first and second data.

18. A method of manufacturing a device, comprising steps of:

exposing a substrate to light using an exposure apparatus of which a condition of an alignment measurement is obtained through a processing method as defined in claim 17;

developing the exposed substrate; and

processing the developed substrate to manufacture the device.

19. A processing apparatus for obtaining a condition of an alignment measurement by an exposure apparatus for exposing a substrate to light, said apparatus comprising:

a storage configured to store first data of a difference between a calculated position of an alignment mark of a sampled area on the substrate calculated based on a plurality of measured positions of a plurality of alignment marks of a plurality of sampled areas on the substrate and the measured position of the alignment mark with respect to each of the plurality of sampled areas, the difference being obtained by the exposure apparatus, and to store second data of an overlay error of a pattern on the substrate with respect to each of the plurality of sampled areas, the pattern being formed by exposing the substrate to the light based on the calculated positions of the plurality of alignment marks by the exposure apparatus, the overlay error being obtained by an overlay inspection apparatus; and

a processor configured to obtain the condition of the alignment measurement based on the first and second data.

20. A program for causing a computer to execute a processing method for obtaining a condition of an alignment measurement by an exposure apparatus for exposing a substrate to light, said method comprising steps of:

acquiring first data of a difference between a calculated position of an alignment mark of a sampled area on the substrate calculated based on a plurality of measured positions of a plurality of alignment marks of a plurality of sampled areas on the substrate and the measured position of the alignment mark with respect to each of the plurality of sampled areas, the difference being obtained by the exposure apparatus;

acquiring second data of an overlay error of a pattern on the substrate with respect to each of the plurality of sampled areas, the pattern being formed by exposing the substrate to the light based on the calculated positions of the plurality of alignment marks by the exposure apparatus, the overlay error being obtained by an overlay inspection apparatus; and

obtaining the condition of the alignment measurement based on the first and second data.