Alignment method and method for producing device using the alignment method

• US 6,481,003 B1
• Filed: 03/29/2001
• Issued: 11/12/2002
• Est. Priority Date: 09/30/1998
• Status: Active Grant

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: Maeda, Koji
• Primary Examiner(s): Lam, Tuan T.
• Assistant Examiner(s): NGUYEN, LONG T
• Application Number:
  US09/806,314
• Time in Patent Office: 593 Days
• Field of Search: 716/19-21, 430/5
• US Class Current: 430/22
• CPC Class Codes: G03F 9/7046 Strategy, e.g. mark, sensor or wavelength selection
• CPC Class Codes: G03F 9/7076 Mark details, e.g. phase grating mark, temporary mark

Abstract

An alignment method for aligning each shot area on a photosensitive substrate with a reticle according to array coordinate predicted by a statistical technique with an improved alignment precision without inviting degradation of throughput, wherein a plurality of alignment marks 29-1, 30-1, 34-1, 35-1 in a short area 27-1 and so forth provided on the n-th wafer 8 (1≦n≦N−1) are measured to carry out the alignment of the shot area with the reticle considering the misalignment of the wafer 8 and the distortion of the shot area 27-1 and so forth, and one alignment mark in a shot are 27-1 or another provided on the (n+k)th wafer 8 (1≦k≦N−n) is measured to carry out the alignment of the shot area with the reticle considering the misalignment of the wafer 8 found from the measurement results, and the distortion of the shot area 27-1 and so forth obtained when the nth wafer 8 is processed.

Claims

1. An alignment method for determining for each of N (N≧

2) substrates, exposure position information for a plurality of areas on said substrates to which a pattern of a mask is transferred, comprising the steps of;

detecting a plurality of marks formed on an nTH substrate (1≦

n≦

N−

1), and in order to determine exposure position information for a plurality of areas on said nTH substrate using a first model function, determining a first parameter, which relates to array of said plurality of areas on said substrate, and a second parameter, which relates to an error of an image formation relationship relative to said pattern of said mask in said area, of said first model function using position information of said detected marks, and

detecting a plurality of marks formed on an (n+k)TH substrate (1≦

k≦

N−

n), and in order to determined exposure position information for a plurality of areas on said (n+k)TH substrate using said first model function, determining said first parameter using a second model function different from said first model function, and position information of marks detected on said (n+k)TH substrate, and using this together with the second parameter determined for said nTH substrate.

2. An alignment method according to claim 1, wherein said second model function has a number of parameters less than that of said first model function.

3. An alignment method according to claim 2, wherein said second model function contains at least said first parameter.

4. An alignment method according to claim 3, wherein said first parameter shows array information for said plurality of areas.

5. An alignment method according to claim 4, wherein said first parameter contains at least two parameters related to scaling, rotation error, orthogonality, or offset of said substrate.

6. An alignment method according to claim 5, wherein said second parameter shows formation information for an area on said substrate.

7. An alignment method according to claim 6, wherein said second parameter contains at least two parameters related to scaling, rotation error, or orthogonality of said area.

8. An alignment method according to claim 1, wherein a plurality of marks in each of at least three specific areas selected from said plurality of areas is detected for said nTH substrate.

9. An alignment method according to claim 1, wherein at least one mark for each of at least two specific areas selected from said plurality of areas is detected for said (n+k)TH substrate.

10. An alignment method according to claim 9, wherein a plurality of marks in said specific area are detected for said (n+k)TH substrate, and one position information of said specific area is determined from position information of said plurality of marks.

11. An alignment method according to claim 1, wherein the total of the marks detected for said (n+k)TH substrate is less than the total of the marks detected for said nth substrate.

12. An alignment method according to claim 11, wherein for said nTH substrate, determining of the first and second parameters of said first model function, and determining of said first parameter using said second model function, is performed based on position information of said detected mark, and the first parameter determined by said second model function is used instead of the first parameter determined by said first model function.

13. An alignment method according to claim 1, wherein said second model function contains only said first parameter, and a deviation between respective set positions and measurement positions in the plurality of specific areas on said substrate where said marks are detected is obtained, and said first parameter is determined so that the sum total of the square of said deviation is a minimum.

14. An alignment method according to claim 1, wherein said nTH substrate is the first substrate, and said (n+K)TH substrate is the second substrate.

15. An alignment method according to claim 1, wherein said (n+k)TH substrate is the third and subsequent substrates, and at the time of determining said exposure position information, at least one of said second parameters respectively determined up to the (n+k−

1)TH substrate is used.

16. An alignment method according to claim 1, wherein said nTH substrate is at least the first substrate of said N substrates.

17. An alignment method according to claim 1, wherein said nTH substrate is at least two substrates among said N substrates which are not consecutive from each other.

18. An exposure method for carrying out an exposure operation using the alignment method according to claim 1, wherein said mask and said substrate are relativity moved based on said determined exposure position information, and a pattern of said mask is respectively transferred to said plurality of areas by a step-and-repeat method or a step-and-scan method.

19. A device manufacturing method comprising the step of:

transferring a device pattern onto a substrate using the exposure method of claim 18.

20. An alignment apparatus which determines for each N (N≧

2) substrates, exposure position information for a plurality of areas on said substrates to which a pattern of a mask is transferred, comprising;

a detector which detects a plurality of marks formed on one of the plurality of substrates;

a first controller which is electrically connected to said detector and which controls the detector to detect a plurality of marks formed on an nTH substrate (1≦

n≦

N−

1), and the first controller in order to determine exposure position information for a plurality of areas on said nTH substrate using a first model function, determines a first parameter and a second parameter of said first model function using position information of said detected marks, the first parameter relates to array of said plurality of areas on said substrate, the second parameter relates to an error of an image formation relationship relative to said pattern of said mask in said area; and

a second controller which is electrically connected to said detector and said first controller and which controls the detector to detect a plurality of marks formed on an (n+k)TH substrate (1≦

k≦

N−

n), and the second controller in order to determine exposure position information for a plurality of areas on said (n+k)TH substrate using said first model function, determines said first parameter using a second model function different from said first mode function, and position information of said marks detected on said (n+k)TH substrate, and uses this determined first parameter together with the second parameter determined for said nTH substrate.

21. An alignment apparatus according to claim 20, wherein said second model function has a number of parameters less than that of said first model function.

22. An alignment apparatus according to claim 20, wherein said first parameter shows array information for said plurality of areas.

23. An alignment apparatus according to claim 22 wherein said first parameter contains at least two parameters related to scaling, rotation error, orthogonality, or offset of said substrate.

24. An alignment apparatus according to claim 20 wherein said second parameter shows formation information for an area on said substrate.

25. An alignment apparatus according to claim 24, wherein said second parameter contains at least two parameters related to scaling, rotation error, or orthogonality of said area.

26. An alignment apparatus according to claim 20, wherein said nTH substrate is the first substrate, and said (n+k)TH substrate is the second substrate.

27. An alignment apparatus according to claim 20, wherein said (n+k)TH substrate is the third and subsequent substrates, and at the time of determining said exposure position information, at least one of said second parameters respectively determined up to the (n−

k−

1)TH substrate is used.

28. An exposure apparatus which carries out an exposure operation using the alignment apparatus according to claim 20, wherein said mask and said substrate are relativity moved based on said determined exposure position information, and a pattern of said mask is respectively transferred to said plurality of areas by a step-and-repeat method or a step-and-scan method.