Exposure apparatus, exposure method, and electronic device manufacturing method

• US 20090042115A1
• Filed: 02/27/2008
• Published: 02/12/2009
• Est. Priority Date: 04/10/2007
• Status: Abandoned Application

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: Shiraishi, Naomasa, Inoue, Hideya
• Application Number:
  US12/071,912
• Publication Number:
  US 20090042115A1
• Time in Patent Office: Days
• US Class Current: 430/22
• CPC Class Codes: G03F 7/70266 Adaptive optics, e.g. deformable optical elements for wavefront control, e.g. for aberration adjustment or correction
• CPC Class Codes: G03F 7/703 Non-planar pattern areas or non-planar masks, e.g. curved masks or substrates
• 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 7/70633 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 7/70783 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
• CPC Class Codes: G03F 9/7088 Alignment mark detection, e.g. TTR, TTL, off-axis detection, array detector, video detection

Abstract

An exposure apparatus for exposing a bright-dark pattern on a substrate via a projection optical system includes a position detection system which detects a plurality of predetermined positions in a unit exposure field of the substrate. A plurality of reference detection positions fall within a range substantially equal to the unit exposure field. A deformation calculation unit calculates a state of deformation in the unit exposure field based on the detection result of the position detection system. A shape modification unit modifies a shape of the bright-dark pattern to be exposed on the substrate based on the deformation state calculated by the deformation calculation unit.

Claims

1. An exposure apparatus that exposes a bright-dark pattern on a substrate via a projection optical system, the exposure apparatus comprising:

a position detection system which detects a plurality of predetermined positions in a unit exposure field of the substrate, wherein a plurality of reference detection positions fall within a range substantially equal to the unit exposure field;

a deformation calculation unit which calculates a state of deformation in the unit exposure field based on the detection result of the position detection system; and

a shape modification unit which modifies a shape of the bright-dark pattern to be exposed on the substrate based on the deformation state calculated by the deformation calculation unit.

2. The exposure apparatus according to claim 1, wherein the position detection system include at least four position detection units, each having a reference detection position that falls within a range substantially equal to the unit exposure field.

3. The exposure apparatus according to claim 1, wherein the position detection system includes a plurality of detection optical systems parallel arranged next to one another, wherein each detection optical system has a reference detection position that falls within a range substantially equal to the unit exposure field.

4. The exposure apparatus according to claim 3, wherein the position detection system includes a plurality of light detection units which detects light passing through the plurality of detection optical systems.

5. The exposure apparatus according to claim 1, wherein the position detection system includes at least one detection optical system and a plurality of light detection units arranged in a detection range of the at least one detection optical system.

6. The exposure apparatus according to claim 1, wherein the position detection system includes a common detection optical system and a plurality of light detection units parallel arranged next to one another to detect light passing through the common detection optical system.

7. The exposure apparatus according to claim 6, wherein the position detection system includes a relative moving device that moves the substrate relative to the common detection optical system.

8. The exposure apparatus according to claim 7, wherein the relative moving device includes a substrate stage which holds the substrate.

9. The exposure apparatus according to claim 1, wherein the position detection system detects each of the predetermined positions without the use of the projection optical system.

10. The exposure apparatus according to claim 1, wherein the shape modification unit includes an optical surface shape modification unit which modifies the shape of at least one optical surface in the projection optical system.

11. The exposure apparatus according to claim 10, wherein the at least one optical surface is arranged at a position near an object plane of the projection optical system, a position optically conjugate to the object plane or near the conjugate position, or a position near an image plane of the projection optical system.

12. The exposure apparatus according to claim 1, wherein the exposure apparatus is configured to form an image of a pattern formed on a mask arranged on the object plane of the projection optical system as the bright-dark pattern on the substrate.

13. The exposure apparatus according to claim 1, wherein the projection optical system has a reduction magnification.

14. The exposure apparatus according to claim 1, wherein the shape modification unit includes a mask surface shape modification unit which modifies the shape of a pattern surface of a mask arranged on an object plane of the projection optical system.

15. The exposure apparatus according to claim 1, wherein the deformation state calculated by the deformation calculation unit includes a high-level deformation state in the substrate or the unit exposure field.

16. The exposure apparatus according to claim 1, wherein:

the exposure apparatus is configured to scan and expose the bright-dark pattern onto the substrate while moving the substrate relative to the projection optical system in a predetermined direction; and

the shape modification unit is configured to modify the shape of the bright-dark pattern in accordance with relative movement of the substrate during the scanning exposure.

17. An exposure method for exposing a bright-dark pattern onto unit exposure fields on a substrate via a projection optical system, the exposure method comprising:

a position detection step of detecting a plurality of predetermined positions in a unit exposure field of the substrate with a position detection system which detects the plurality of predetermined positions that fall within a range substantially equal to one of the unit exposure fields;

a deformation calculation step of calculating a state of deformation in the unit exposure field based on information related to the plurality of predetermined positions obtained in the position detection step; and

a shape modification step of modifying a shape of the bright-dark pattern to be exposed on the substrate based on the deformation state obtained in the deformation calculation step.

18. The exposure method according to claim 17, wherein the position detection step includes detecting at least four predetermined positions.

19. The exposure method according to claim 17, wherein the position detection step includes detecting the plurality of predetermined positions with a plurality of detection optical systems parallel arranged next to one another in the position detection system.

20. The exposure method according to claim 19, wherein the position detection step includes detecting light passing through the plurality of detection optical systems with a plurality of position detection units.

21. The exposure method according to claim 17, wherein the position detection step includes detecting light passing through at least one detection optical system with a plurality of light detection units included in the position detection system and arranged in a detection range of the at least one detection optical system.

22. The exposure method according to claim 17, wherein the position detection step includes detecting light passing through a common detection optical system included in the position detection system with a plurality of light detection units parallel arranged next to one another.

23. The exposure method according to claim 22, wherein the position detection step includes detecting the plurality of predetermined positions while moving the substrate relative to the common detection optical system.

24. The exposure method according to claim 17, wherein the position detection step includes detecting the plurality of predetermined positions without the use of the projection optical system.

25. The exposure method according to claim 17, wherein the shape modification step includes an optical surface shape modification step of modifying the shape of at least one optical surface in the projection optical system.

26. The exposure method according to claim 25, wherein the shape modification step includes modifying the shape of an optical surface arranged at a position near an object plane of the projection optical system, a position optically conjugate to the object plane or near the conjugate position, or a position near an image plane of the projection optical system.

27. The exposure method according to claim 17, wherein the bright-dark pattern formed on the substrate is an image of a pattern formed on a mask.

28. The exposure method according to claim 17, wherein the bright-dark pattern is exposed on the substrate with the projection optical system that has a reduction magnification.

29. The exposure method according to claim 17, wherein the shape modification step includes a mask surface shape modification step of modifying the shape of a pattern surface of a mask arranged on an object plane of the projection optical system.

30. The exposure method according to claim 17, wherein the deformation state obtained in the deformation calculation step includes a high-level deformation state in the substrate or the unit exposure field.

31. The exposure method according to claim 17, further comprising:

a scanning exposure step of scanning and exposing the bright-dark pattern onto the substrate while moving the substrate relative to the projection optical system in a predetermined direction;

wherein the shape modification step includes modifying the shape of the bright-dark pattern in accordance with relative movement of the substrate during the scanning exposure.

32. A method for manufacturing an electronic device, the method comprising:

a lithography step using the exposure method according to claim 17.