Exposure apparatus and method

• US 6,590,634 B1
• Filed: 11/21/2000
• Issued: 07/08/2003
• Est. Priority Date: 11/28/1996
• Status: Expired due to Fees

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: Nishi, Kenji, Ota, Kazuya
• Primary Examiner(s): NGUYEN, HUNG
• Application Number:
  US09/716,405
• Time in Patent Office: 959 Days
• Field of Search: 355/53, 355/67, 355/72-76, 355/55, 310/10, 310/12, 414/936, 414/941, 356/399-401, 250/548
• US Class Current: 355/53
• CPC Class Codes: G03F 7/70216 Mask projection systems
• CPC Class Codes: G03F 7/70358 Scanning exposure, i.e. relative movement of patterned beam and workpiece during imaging
• CPC Class Codes: G03F 7/70425 Imaging strategies, e.g. for increasing throughput or resolution, printing product fields larger than the image field or compensating lithography- or non-lithography errors, e.g. proximity correction, mix-and-match, stitching or double patterning
• CPC Class Codes: G03F 7/70716 Stages
• CPC Class Codes: G03F 7/70733 Handling masks and workpieces, e.g. exchange of workpiece or mask, transport of workpiece or mask
• CPC Class Codes: G03F 9/70 for microlithography measuring printed patterns for monitoring overlay G03F7/70633 or focus G03F7/70641; projection system adjustment G03F7/70258; position control G03F7/70775
• CPC Class Codes: G03F 9/7003 Alignment type or strategy, e.g. leveling, global alignment
• CPC Class Codes: G03F 9/7015 Reference, i.e. alignment of original or workpiece with respect to a reference not on the original or workpiece
• CPC Class Codes: G03F 9/7026 Focusing
• CPC Class Codes: G03F 9/7088 Alignment mark detection, e.g. TTR, TTL, off-axis detection, array detector, video detection

Abstract

Two stages (WS1, WS2) holding wafers can independently move between a positional information measuring section (PIS) under an alignment system (24a) and an exposing section (EPS) under a projection optical system (PI). The wafer exchange and alignment are performed on the stage (WS1), during which wafer (W2) is exposed on the stage (WS2). A position of each shot area of wafer (WS1) is obtained as a relative position with respect to a reference mark formed on the stage WS1 in the section (PIS). Relative positional information can be used for the alignment with respect to an exposure pattern when the wafer (WS1) is moved to the section (EPS) to be exposed. Therefore, it is not necessary that a stage position is observed continuously in moving the stage. Exposure operations are performed in parallel by the two wafer stages (WS1) and (WS2) so as to improve the throughput.

Claims

1. An exposure apparatus for forming a predetermined pattern on a sensitive substrate, wherein the exposure apparatus comprises:

a first holding member which holds a sensitive substrate;

a second holding member which holds a sensitive substrate;

a first movable member which is used commonly for the first and second holding members, and which is movable in a two-dimensional plane while supporting one of the first and second holding members in order for an exposure to be performed of the sensitive substrate held by the one holding member; and

a second movable member which is used commonly for the first and second holding members, and which is movable in a two-dimensional plane while supporting the other of the first and second holding members in order for a measurement to be performed of the sensitive substrate held by the holding member;

a first interferometer system which obtains positional information of the one holding member held by the first movable member; and

a second interferometer system which obtains positional information of the other holding member held by the second movable member;

each of the first and second holding members having a reflective surface used for the first and second interferometer systems; and

the first and second movable members alternately support the first and second holding members.

2. An exposure apparatus according to claim 1, further comprising an exchanging mechanism which exchanges the one holding member supported by the first movable member and the other holding member supported by the second movable member.

3. An exposure apparatus according to claim 1, wherein the first and second movable members are moved by an electromagnetic force.

4. An exposure apparatus according to claims 1, wherein reflective surfaces used for the first and second interferometer systems are formed on the first and second holding members, respectively.

5. An exposure apparatus according to claim 1, wherein the first and second movable members are supported on a common base.

6. An exposure apparatus according to claim 5, further comprising a gas-bearing which supports the first and second movable members on the common base.

7. An exposure apparatus according to claim 1, wherein the exposure apparatus performs a scanning-exposure while moving the sensitive substrates relative to an exposure light.

8. An exposure apparatus according to claim 1, wherein the measurement includes a determination of positional information about a plurality of defined areas on the sensitive substrate.

9. An exposure apparatus according to claim 1, wherein the measurement includes a detection of an alignment mark on the sensitive substrate.

10. An exposure apparatus according to claim 9, herein the measurement includes a detection of focusing information of the substrate held on the other holding member supported by the second movable member.

11. An exposure apparatus according to claim 1, wherein the first movable member is moved without the second interferometer system, and the second movable member is moved without the first interferometer system.

12. An exposure apparatus according to claim 11, wherein the first and second movable members move on a common base.

13. An exposure apparatus according to claim 1, wherein the measurement includes a determination of positional relationship between a plurality of defined areas on the substrate held on the other holding member supported by the second movable member and a reference provided on the other holding member supported by the second movable member, and wherein after exchanging the holding members so that the one holding member is supported by the second movable member and the other holding member is supported by the first movable member, the reference provided on the other holding member is detected in order for alignment of the plurality of defined areas on the other holding member supported by the first holding member.

14. An exposure apparatus according to claim 13, wherein the first movable member is moved without the second interferometer system, and the second movable member is moved without the first interferometer system.

15. An exposure apparatus according to claim 14, wherein the first and second movable members move on a common base.

16. A micro-device manufacturing method including a lithography process utilizing the exposure apparatus defined in claim 1.

35. An exposure apparatus according to claim 1, further comprising:

a position control device, functionally associated with the first and second movable members, which controls the first and second movable members without using the first and second interferometer systems, when the first and second holding members are uncoupled from the first and second movable members, respectively.

36. An exposure apparatus according to claim 35, wherein the position control device moves the first and second movable members without using the first and second interferometer systems, when the first and second holding members are uncoupled from the first and second movable members, respectively.

37. An exposure apparatus according to claim 35, wherein the first and second movable members are stopped by the position control device without using the first and second interferometer systems, when the first and second holding members are uncoupled from the first and second movable members, respectively.

38. An exposure apparatus according to claim 37, wherein the position control device includes stoppers.

39. An exposure apparatus according to claim 35, wherein the position control device includes a measuring device which detects positional information of the first and second movable members in order to control the first and second movable members without using the first and second interferometer systems, when the first and second holding members are uncoupled from the first and second movable members, respectively.

40. An exposure apparatus according to claim 39, wherein the measuring device includes an encoder.

41. An exposure apparatus according to claim 35, further comprising:

a driving system which moves the first and second movable members, respectively.

42. An exposure apparatus according to claim 41, further comprising:

a switching device having coupling members which are respectively coupled to the first and second holding members in order to carry out the first and second holding members between the first movable member and the second movable member.

17. An exposure method for forming a predetermined pattern on sensitive substrate, the method comprising:

exposing a sensitive substrate which is held on a first holding member, while moving a first movable member which supports said first holding member;

monitoring positional information of the first holding member which is supported by the first movable member by using a first interferometer system;

measuring alignment information of a sensitive substrate which is held on a second holding member, while moving a second movable member which supports said second holding member;

monitoring positional information of the second holding member which is supported by the second movable member by using a second interferometer system;

exchanging the holding members so that the first holding member is supported by the second movable member and the second holding member is supported by the first movable member;

exposing, after the exchange, the sensitive substrate held on the second holding member, while moving said first movable member which supports the second holding member; and

monitoring, after the exchange, positional information of the second holding member which is supported by the first movable member by using said first interferometer system, each of the first and second holding members having a reflective surface used for the first and second interferometer systems.

18. An exposure method according to claim 17, wherein said first and second movable members are moved by an electromagnetic force.

19. An exposure method according to claim 17, wherein reflective surfaces used for the first and second interferometer systems are formed on the first and second holding members, respectively.

20. An exposure method according to claim 17, wherein each of said first and second holding members has a reference, and wherein the reference of one of said holding members which is supported by the first movable member is detected prior to an exposure.

21. An exposure method according to claim 17, wherein said exposure is performed by a scanning-exposure method.

22. An exposure method according to claim 17, wherein said first interferometer system measures yawing and pitching.

23. An exposure method according to claim 22, wherein said second interferometer system measures yawing and pitching.

24. An exposure method according to claim 23, wherein the alignment information includes positional relationship between a plurality of defined areas on the substrate held on the second holding member supported by the second movable member and a reference provided on the second holding member supported by the second movable member, and wherein after the exchange, the reference provided on the second holding member is detected in order for alignment of the plurality of defined areas on the second holding member supported by the first holding member.

25. An exposure method according to claim 24, wherein the first movable member is moved without the second interferometer system, and the second movable member is moved without the first interferometer system.

26. An exposure method according to claim 25, wherein the first and second movable members are moved on a common base.

27. An exposure method according to claim 23, wherein the first movable member is moved without the second interferometer system, and the second movable member is moved without the first interferometer system.

28. An exposure method according to claim 27, wherein the first and second movable members are moved on a common base.

29. An exposure method according to claim 17, wherein said alignment information is obtained by detecting a plurality of marks on the sensitive substrate.

30. An exposure method according to claim 17, wherein said exposure of the substrate held on the first holding member is performed, while executing said measurement of the alignment information of the substrate held on the second holding member.

31. A device manufacturing method including an exposure process utilizing the method defined in claim 17.

32. An exposure method according to claim 17, wherein the alignment information includes positional relationship between a plurality of defined areas on the substrate held on the second holding member supported by the second movable member and a reference provided on the second holding member supported by the second movable member, and wherein after the exchange, the reference provided on the second holding member is detected in order for alignment of the plurality of defined areas on the second holding member supported by the first holding member.

33. An exposure method according to claim 32, wherein the first movable member is moved without the second interferometer system, and the second movable member is moved without the first interferometer system.

34. An exposure method according to claim 33, wherein the first and second movable members are moved on a common base.

43. An exposure method according to claim 17, further comprising:

controlling positions of the first and second movable members without using the first and second interferometer systems, when the first and second holding members are uncoupled from the first and second movable members, respectively.

44. An exposure method according to claim 43, wherein the first and second movable members are moved without using the first and second interferometer systems, when the first and second holding members are uncoupled from the first and second movable members, respectively.

45. An exposure method according to claim 43, wherein the first and second movable members are stopped without using the first and second interferometer systems, when the first and second holding members are uncoupled from the first and second movable members, respectively.

46. An exposure method according to claim 45, wherein the first and second movable members are stopped by stoppers.

47. An exposure method according to claim 43, further comprising:

detecting positional information of the first and second movable members without using the first and second interferometer systems, when the first and second holding members are uncoupled from the first and second movable members, respectively.

48. An exposure method according to claim 47, wherein the positional information of the first and second movable members are optically detected, when the first and second holding members are uncoupled from the first and second movable members, respectively.

49. An exposure method according to claim 48, wherein the positional information of the first and second movable members are optically detected by using an encoder.

50. An exposure method according to claim 43, further comprising:

physically connecting a switching device to the first and second holding members in order to carry the first and second holding members, which are uncoupled from the first and second movable members, between the first movable member and the second movable member, respectively.