SPATIAL LIGHT MODULATING UNIT, ILLUMINATION OPTICAL SYSTEM, EXPOSURE APPARATUS, AND DEVICE MANUFACTURING METHOD

• US 20110027724A1
• Filed: 10/11/2010
• Published: 02/03/2011
• Est. Priority Date: 04/11/2008
• Status: Abandoned Application

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: TANAKA, Hirohisa
• Application Number:
  US12/901,666
• Publication Number:
  US 20110027724A1
• Time in Patent Office: Days
• US Class Current: 430/325
• CPC Class Codes: G02B 26/0833 the reflecting element being a micromechanical device, e.g. a MEMS mirror, DMD G02B26/0825 takes precedence; micromechanical devices in general B81B
• CPC Class Codes: G02B 27/0977 Reflective elements
• CPC Class Codes: G03F 7/70116 Off-axis setting using a programmable means, e.g. liquid crystal display [LCD], digital micromirror device [DMD] or pupil facets

Abstract

There is disclosed a spatial light modulating unit comprising, a spatial light modulator having a plurality of optical elements arrayed two-dimensionally and controlled individually, and an exit-side optical system which guides light having traveled via the plurality of optical elements of the spatial light modulator, wherein the exit-side optical system is configured so that zero-order light having traveled via a surface portion other than the plurality of optical elements and approximately parallel to an array plane where the plurality of optical elements are arrayed, does not pass through an entrance pupil of the exit-side optical system.

Claims

1. A spatial light modulating unit comprising:

a spatial light modulator having a plurality of optical elements arrayed two-dimensionally and controlled individually; and

an exit-side optical system which guides light having traveled via the plurality of optical elements of the spatial light modulator,

wherein the exit-side optical system is configured so that zero-order light having traveled via a surface portion other than the plurality of optical elements and approximately parallel to an array plane where the plurality of optical elements are arrayed, does not pass through an entrance pupil of the exit-side optical system.

2. The spatial light modulating unit according to claim 1, comprising an entrance-side optical system which guides light to the plurality of optical elements of the spatial light modulator.

3. The spatial light modulating unit according to claim 2, wherein optical surfaces of the plurality of optical elements in a standard state in which a parallel beam incident along an optical axis of the entrance-side optical system to the plurality of optical elements is guided via the plurality of optical elements and along an optical axis of the exit-side optical system, are inclined around a predetermined axis relative to the array plane.

4. The spatial light modulating unit according to claim 3, wherein the optical surfaces of the plurality of optical elements have a contour in which a length in a direction perpendicular to the predetermined axis is larger than a length in a direction parallel to the predetermined axis.

5. The spatial light modulating unit according to claim 2, wherein the entrance-side optical system has a first deflecting member arranged on the spatial light modulator side, and wherein the exit-side optical system has a second deflecting member arranged on the spatial light modulator side.

6. The spatial light modulating unit according to claim 5, wherein an optical axis of the entrance-side optical system extending from the first deflecting member to the front side and an optical axis of the exit-side optical system extending from the second deflecting member to the rear side are coincident or parallel with each other.

7. The spatial light modulating unit according to claim 5, wherein the second deflecting member comprises a reflecting surface, and

wherein the zero-order light having traveled via the surface portion other than the plurality of optical elements and approximately parallel to the array plane where the plurality of optical elements are arrayed, travels to the outside of the reflecting surface of the second deflecting member.

8. The spatial light modulating unit according to claim 2, wherein the entrance-side optical system is configured so that the zero-order light having traveled via the surface portion other than the plurality of optical elements and approximately parallel to the array plane where the plurality of optical elements are arrayed, does not pass through the entrance-side optical system.

9. The spatial light modulating unit according to claim 1, wherein the spatial light modulator has a plurality of mirror elements arrayed two-dimensionally, and a drive unit which individually controls and drives postures of the plurality of mirror elements.

10. The spatial light modulating unit according to claim 9, wherein the drive unit continuously or discretely varies orientations of the plurality of mirror elements.

11. The spatial light modulating unit according to claim 1, which is used together with an illumination optical system which illuminates an illumination target surface on the basis of light from a light source, the spatial light modulating unit guiding the light from the light source to a distribution forming optical system in the illumination optical system to form a predetermined light intensity distribution on an illumination pupil conjugate with the entrance pupil.

12. The spatial light modulating unit according to claim 11, wherein the illumination optical system is used in combination with a projection optical system which forms a plane optically conjugate with the illumination target surface, and wherein the illumination pupil is a position optically conjugate with an aperture stop of the projection optical system.

13. The spatial light modulating unit according to claim 1, wherein the surface portion other than the plurality of optical elements and approximately parallel to the array plane where the plurality of optical elements are arrayed, is located between the plurality of optical elements.

14. An illumination optical system which illuminates an illumination target surface on the basis of light from a light source, said illumination optical system comprising:

the spatial light modulating unit as set forth in claim 1; and

a distribution forming optical system which forms a predetermined light intensity distribution on an illumination pupil conjugate with the entrance pupil, based on a flux of light having traveled via the spatial light modulator.

15. The illumination optical system according to claim 14, wherein the distribution forming optical system has an optical integrator, and a condensing optical system arranged in an optical path between the optical integrator and the spatial light modulating unit.

16. The illumination optical system according to claim 14, which is used in combination with a projection optical system which forms a plane optically conjugate with the illumination target surface, wherein the illumination pupil is a position optically conjugate with an aperture stop of the projection optical system.

17. An exposure apparatus comprising the illumination optical system as set forth in claims 14 for illuminating a predetermined pattern, wherein the predetermined pattern is transferred onto a photosensitive substrate to effect exposure thereof.

18. A device manufacturing method comprising:

transferring the predetermined pattern onto the photosensitive substrate to effect exposure thereof, using the exposure apparatus as set forth in claim 17;

developing the photosensitive substrate on which the predetermined pattern is transferred, to form a mask layer of a shape corresponding to the predetermined pattern on a surface of the photosensitive substrate; and

processing the surface of the photosensitive substrate through the mask layer.

19. A spatial light modulator which modulates light incident thereto from a first optical system and guides the light to a second optical system,

the spatial light modulator comprising a plurality of optical elements arrayed two-dimensionally and controlled individually,

wherein optical surfaces of the plurality of optical elements in a standard state in which a parallel beam incident along an optical axis of the first optical system to the plurality of optical elements is guided via the plurality of optical elements and along an optical axis of the second optical system, are inclined around a predetermined axis relative to an array plane where the plurality of optical elements are arrayed.

20. The spatial light modulator according to claim 19, comprising a plurality of mirror elements arrayed two-dimensionally, and a drive unit which individually controls and drives postures of the plurality of mirror elements.

21. The spatial light modulator according to claim 20, wherein the drive unit continuously or discretely varies orientations of the plurality of mirror elements.

22. The spatial light modulator according to claim 19, which is used together with an illumination optical system which illuminates an illumination target surface on the basis of light from a light source, the spatial light modulator guiding the light from the light source to a distribution forming optical system in the illumination optical system to form a predetermined light intensity distribution on an illumination pupil of the illumination optical system.

23. The spatial light modulator according to claim 22, wherein the illumination optical system is used in combination with a projection optical system which forms a plane optically conjugate with the illumination target surface, and wherein the illumination pupil is a position optically conjugate with an aperture stop of the projection optical system.

24. An illumination optical system which illuminates an illumination target surface on the basis of light from a light source, said illumination optical system comprising:

the spatial light modulator as set forth in claim 19; and

a distribution forming optical system which forms a predetermined light intensity distribution on an illumination pupil of the illumination optical system, based on a flux of light having traveled via the spatial light modulator.

25. The illumination optical system according to claim 24, wherein the distribution forming optical system has an optical integrator, and a condensing optical system arranged in an optical path between the optical integrator and the spatial light modulator.

26. The illumination optical system according to claim 24, which is used in combination with a projection optical system which forms a plane optically conjugate with the illumination target surface, wherein the illumination pupil is a position optically conjugate with an aperture stop of the projection optical system.

27. An exposure apparatus comprising the illumination optical system as set forth in claim 24 for illuminating a predetermined pattern, wherein the predetermined pattern is transferred onto a photosensitive substrate to effect exposure thereof.

28. A device manufacturing method comprising:

an exposure step of transferring the predetermined pattern onto the photosensitive substrate to effect exposure thereof, using the exposure apparatus as set forth in claim 27;

a development step of developing the photosensitive substrate on which the predetermined pattern is transferred, to form a mask layer of a shape corresponding to the predetermined pattern on a surface of the photosensitive substrate; and

a processing step of processing the surface of the photosensitive substrate through the mask layer.