ILLUMINATION OPTICAL APPARATUS, EXPOSURE APPARATUS, AND DEVICE MANUFACTURING METHOD

• US 20090128886A1
• Filed: 10/13/2008
• Published: 05/21/2009
• Est. Priority Date: 10/12/2007
• Status: Active Grant

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: HIROTA, Hiroyuki
• Granted Patent: US 9,097,981 B2
• Time in Patent Office: Days
• US Class Current: 359/291
• CPC Class Codes: G02B 26/02 for controlling the intensity of light G02B26/004 takes precedence
• CPC Class Codes: G03F 7/70083 Non-homogeneous intensity distribution in the mask plane
• 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
• CPC Class Codes: G03F 7/70158 Diffractive optical elements
• CPC Class Codes: G03F 7/70291 Addressable masks, e.g. spatial light modulators [SLMs], digital micro-mirror devices [DMDs] or liquid crystal display [LCD] patterning devices

Abstract

An illumination optical apparatus guides exposure light emitted from an exposure light source, to an illumination target object. The illumination optical apparatus has a plurality of spatial light modulation members arranged in an array form, and each spatial light modulation member is so configured that a plurality of reflecting optical elements each including a movable reflecting surface are arranged in an array form. At least one of the spatial light modulation members is arranged in an optical path of the light emitted from the light source.

Claims

1. An illumination optical apparatus which guides light emitted from a light source and traveling along a predetermined optical path, to an illumination target object, the illumination optical apparatus comprising:

a plurality of spatial light modulation members in which a plurality of reflecting optical elements each including a movable reflecting surface are arranged in an array form;

wherein at least one of the spatial light modulation members is arranged in the optical path.

2. The illumination optical apparatus according to claim 1, wherein the spatial light modulation members are arranged in the array form so that every spatial light modulation member is located in the optical path.

3. The illumination optical apparatus according to claim 1, further comprising a moving mechanism which moves the spatial light modulation members in a direction intersecting with an axis of the light emitted from the light source, in the optical path.

4. The illumination optical apparatus according to claim 3, further comprising:

a light intensity detector which is disposed on the farther side from the light source with respect to a position where the spatial light modulation members are arranged, and which detects an intensity of light having passed via the spatial light modulation member; and

a controller which drives the moving mechanism on the basis of an output from the light intensity detector.

5. The illumination optical apparatus according to claim 3, further comprising:

a distribution forming optical system which condenses light having passed via the spatial light modulation member, to form a predetermined light intensity distribution on an illumination pupil of the illumination optical apparatus;

a light intensity distribution detector which detects the light intensity distribution formed on the illumination pupil; and

a controller which drives the moving mechanism on the basis of an output from the light intensity distribution detector.

6. The illumination optical apparatus according to claim 1, further comprising a beam splitter which is disposed on the light source side with respect to the spatial light modulation members and which splits the light emitted from the light source, into a plurality of beams,

wherein the spatial light modulation members are arranged in respective optical paths of the beams.

7. The illumination optical apparatus according to claim 6, further comprising a restraining member which is disposed between the spatial light modulation members and the beam splitter and which restrains return light from the spatial light modulation members from entering the beam splitter.

8. The illumination optical apparatus according to claim 6, wherein there is no optical member with power arranged in an optical path between the beam splitter and the spatial light modulation members.

9. The illumination optical apparatus according to claim 1, wherein the plurality of spatial light modulation members comprise a first spatial light modulation member arranged at a first position, and a second spatial light modulation member arranged at a second position different from the first position, and

wherein an axis of the optical path of the light emitted from the light source is interposed between the first and second positions.

10. The illumination optical apparatus according to claim 9, further comprising a beam splitter which is disposed on the light source side with respect to the spatial light modulation members and which splits the light emitted from the light source, into a plurality of beams,

wherein the beam splitter splits the light emitted from the light source, into the plurality of beams in a plane including the axis of the optical path of the light emitted from the light source.

11. The illumination optical apparatus according to claim 1, further comprising a distribution forming optical system which condenses light having passed via the spatial light modulation member, to form a predetermined light intensity distribution on an illumination pupil of the illumination optical apparatus.

12. The illumination optical apparatus according to claim 11, wherein the plurality of spatial light modulation members are so configured as to prevent zero-order light having passed via a surface portion other than the plurality of reflecting optical elements and substantially parallel to an arrangement surface on which the plurality of reflecting optical elements are arranged, from passing through an entrance pupil of the distribution forming optical system.

13. The illumination optical apparatus according to claim 12, wherein the distribution forming optical system is so configured as to be able to superimpose at least a part of a beam having passed via one of the plurality of spatial light modulation members and at least a part of another one of the plurality of spatial light modulation members, on the illumination pupil.

14. The illumination optical apparatus according to claim 1, wherein each of the reflecting optical elements is movable for changing an angle of inclination of the reflecting surface relative to an axis of light incident to the reflecting surface.

15. The illumination optical apparatus according to claim 14, wherein each of the reflecting optical elements forming at least one spatial light modulation member out of the spatial light modulation members is rotatable around a first axis or around an axis parallel to the first axis, and

wherein each of the reflecting optical elements forming another spatial light modulation member different from said at least one spatial light modulation member is rotatable around a second axis intersecting with the first axis, or around an axis parallel to the second axis.

16. An exposure apparatus comprising:

the illumination optical apparatus as set forth in claim 1;

a holding mechanism to hold an illumination target object on which a predetermined pattern is formed; and

a projection optical device for projecting a pattern image formed when the light emitted from the light source is guided through the illumination optical apparatus onto the illumination target object, onto a substrate coated with a photosensitive material.

17. A device manufacturing method comprising:

performing exposure of the predetermined pattern on the substrate, using the exposure apparatus as set forth in claim 16;

developing the substrate to form a mask layer in a shape corresponding to the predetermined pattern on a surface of the substrate, after performing exposure of the predetermined pattern on the substrate; and

processing the surface of the substrate through the mask layer, after developing the substrate.

18. An illumination optical apparatus which guides light emitted from a light source and traveling along a predetermined optical path, to an illumination target object, the illumination optical apparatus comprising:

a spatial light modulation member, arranged in the optical path, in which a plurality of reflecting optical elements each including a movable reflecting surface are arranged in an array form; and

a diffractive optical element arranged in the optical path,

wherein light from the light source reaches to the illumination target object via the spatial light modulation member and the diffractive optical element.

19. The illumination optical apparatus according to claim 18, wherein the diffractive optical element and the spatial light modulation member arranged in a series.

20. The illumination optical apparatus according to claim 19, wherein the diffractive optical element is disposed between the light source and the spatial light modulation member.