Method for calibrating or qualifying a lithographic apparatus or part thereof, and device manufacturing method

• US 20070009814A1
• Filed: 07/11/2005
• Published: 01/11/2007
• Est. Priority Date: 07/11/2005
• Status: Active Grant

• Current Assignee: ASML Netherlands BV (ASML Holding NV)
• Original Assignee: ASML Netherlands BV (ASML Holding NV)
• Inventors: Oesterholt, Rene
• Granted Patent: US 7,374,957 B2
• Time in Patent Office: Days
• US Class Current: 430/30
• CPC Class Codes: G03F 7/70508 Data handling in all parts of the microlithographic apparatus, e.g. handling pattern data for addressable masks or data transfer to or from different components within the exposure apparatus
• CPC Class Codes: G03F 7/70516 Calibration of components of the microlithographic apparatus, e.g. light sources, addressable masks or detectors
• 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 7/70641 Focus
• CPC Class Codes: G03F 7/70783 Handling stress or warp of chucks, masks or workpieces, e.g. to compensate for imaging errors or considerations related to warpage of masks or workpieces due to their own weight

Abstract

A system and method are provided for qualifying or calibrating lithographic apparatus or parts therefor, using a predetermined objective criterion such as Chauvenet'"'"'s criterion is used to reject measurement points, individually, by field or by substrate.

Claims

1. A method of calibrating a lithographic apparatus, the method comprising:

measuring a value of a parameter indicative of the performance of the lithographic apparatus at a plurality of different (i) positions, (ii) times (iii) settings, or any combination of (i)-(iii) of the apparatus to generate a first data set comprising a plurality of measurement values;

generating a second data set that is a subset of the first data set using a predetermined criteria to select data values of said first data set for inclusion in said second data set; and

using a predetermined statistical process to derive a calibration value from the second data set.

2. A method according to claim 1 wherein the parameter comprises one of the overlay performance in one or more dimensions and the focus performance.

3. A method according to claim 1 wherein the plurality of measurements are taken at different positions spaced across an area of a substrate.

4. A method according to claim 1 wherein the plurality of measurements are taken using a plurality of different substrates.

5. A method according to claim 4 wherein the plurality of measurements include a plurality of measurements taken on each of said plurality of different substrates.

6. A method according to claim 5 wherein the predetermined criterion is applied individually to select or reject each measurement of each substrate and then a second criterion is applied collectively to groups of measurements of each substrate to select or reject all measurements of a corresponding group.

7. A method according to claim 6 wherein the second predetermined criterion comprises comparison of a proportion of measurements of each group that have been rejected by the predetermined criterion to a threshold.

8. A method according to claim 6 wherein each of said groups comprises all measurements for the respective substrate.

9. A method according to claim 6 wherein each of said groups comprise all measurements for a field of the respective substrate.

10. A method according to claim 1 wherein the predetermined criterion is Chauvenet'"'"'s criterion or Peirce'"'"'s criterion.

11. A method according to claim 1 wherein the predetermined criterion is an absolute threshold.

12. A device manufacturing method using a lithographic apparatus arranged to transfer a pattern from a patterning device onto a substrate, the method comprising:

calibrating the lithographic apparatus by;

measuring a value of a parameter indicative of a performance of the lithographic apparatus at a plurality of different (i) positions, (ii) times, (iii) settings, or any combination of (i)-(iii) of the apparatus to generate a first data set comprising a plurality of measurement values;

generating a second data set that is a subset of the first data set using a predetermined criteria to select data values of said first data set for inclusion in said second data set; and

using a predetermined statistical process to derive a calibration value from the second data set; and

transferring a device pattern onto a second substrate using the calibration value to adjust a parameter of the apparatus.

13. A method of qualifying a part for a lithographic apparatus, the method comprising:

measuring a value of a parameter indicative of a desired quality of the part at a plurality of different (i) positions, (ii) times, or a combination of (i) and (ii) to generate a first data set comprising a plurality of measurement values;

generating a second data set that is a subset of the first data set using a predetermined criteria to select data values of said first data set for inclusion in said second data set; and

using a predetermined statistical process to derive a qualification value from the second data set, whereby the fitness for use of the part can be judged on the basis of the qualification value.

14. A method according to claim 13 wherein the plurality of measurements are taken at different positions spaced across an area of a substrate.

15. A method according to claim 13 wherein the plurality of measurements are taken using a plurality of different substrates.

16. A method according to claim 15 wherein the plurality of measurements include a plurality of measurements taken on each of said plurality of substrates.

17. A method according to claim 16 wherein the predetermined criterion is applied individually to select or reject each measurement of each substrate and then a second criterion is applied collectively to groups of measurements of each substrate to select or reject all measurements of that group.

18. A method according to claim 17 wherein the second predetermined criterion comprises comparison of a proportion of measurements of each group that have been rejected by the predetermined criterion to a threshold.

19. A method according to claim 17 wherein each of said groups comprises all measurements for the respective substrate.

20. A method according to claim 17 wherein each of said groups comprise all measurements for a field of the respective substrate.

21. A method according to claim 13 wherein the predetermined criterion is Chauvenet'"'"'s criterion or Peirce'"'"'s criterion.

22. A method according to claim 13 wherein the predetermined criterion is an absolute threshold.

23. A method according to claim 13 wherein the part is a substrate holder and the parameter is the flatness of the substrate holder.

24. A method according to claim 13 wherein the part is a projection system and the parameter is non-correctable error.

25. A method according to claim 13 wherein the part is a reference substrate holder and the parameter is the flatness of the reference substrate.