Illumination optical apparatus, exposure apparatus, and device manufacturing method

• US 9,097,981 B2
• Filed: 10/13/2008
• Issued: 08/04/2015
• Est. Priority Date: 10/12/2007
• Status: Active Grant

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: Hirota, Hiroyuki
• Primary Examiner(s): KREUTZER, COLIN WRIGHT
• Application Number:
  US12/250,519
• Publication Number:
  US 20090128886A1
• Time in Patent Office: 2,486 Days
• Field of Search: 355/53, 355 67- 68, 355/71, 355/75, 355/77, 359/385, 359871-872, 359850-851, 250/492.2
• US Class Current: 1/1
• 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 system which illuminates a plane to be illuminated with illumination light from a light source, the illumination optical system comprising, in order from the light source side:

an optical element having a plurality of optical surfaces for splitting the illumination light into a plurality of beams;

a first optical system which condenses the plurality of the beams and guides the condensed plurality of the beams to a predetermined plane, the first optical system refocusing the plurality of beams split by the optical element such that first paths of the plurality of beams prior to entering the first optical system are different from second paths of the plurality of beams after exiting the first optical system;

a spatial optical modulator arranged on the predetermined plane and having a plurality of reflecting optical elements each of which has a movable reflection surface arranged to receive a respective beam of the plurality of beams traversing the second paths; and

a second optical system arranged to distribute a plurality of light beams from the movable reflection surface of each of the reflecting optical elements at a pupil position of the illumination optical system or a position optically conjugate with the pupil position and to form a spatial light distribution at the pupil position or the position optically conjugate with the pupil position.

2. The illumination optical system according to claim 1, wherein

the second optical system has an optical plane array having a plurality of optical surfaces two-dimensionally arranged.

3. The illumination optical system according to claim 2, wherein

the plurality of the optical surfaces of the optical plane array is arranged along a plane crossing an optical path adjacent to the pupil position or adjacent to the position optically conjugate with the pupil position.

4. The illumination optical apparatus according to claim 2, wherein

the second optical system comprises a condenser optical system arranged between the spatial optical modulator and the optical plane array.

5. The illumination optical apparatus according to claim 4, wherein

the condenser optical system converts angle information of an incident light into a position information thereof.

6. The illumination optical system according to claim 4, wherein

a back focal position of the condenser optical system is positioned near a plane on which the optical plane array is arranged.

7. The illumination optical system according to claim 2, wherein

the optical plane array has a plurality of lens surfaces two-dimensionally arranged.

8. The illumination optical system according to claim 1, further comprising

a third optical system arranged between the second optical system and the plane to be illuminated, which performs Kohler illumination to the plane to be illuminated with light distributed at the pupil position or at the position optically conjugate with the pupil position by the second optical system.

9. The illumination optical system according to claim 1, wherein

the illumination optical system is used with a projection optical system which forms a pattern image arranged in the plane to be illuminated on a substrate, and the pupil position is optically conjugate with a pupil plane of the projection optical system.

10. The illumination optical system according to claim 1, wherein

the optical element has a plurality of lens surfaces arranged in a plane crossing an optical path of the illumination light.

11. The illumination optical system according to claim 1, wherein

an optical axis of the second optical system intersects with the predetermined plane at a non-perpendicular angle.

12. The illumination optical system according to claim 1, wherein

a plane containing the plurality of optical surfaces of the optical element is parallel with the predetermined plane.

13. The illumination optical system according to claim 1, wherein

the first optical system includes a relay optical system.

14. An illumination method of illuminating a plane to be illuminated with illumination light from a light source, the method comprising:

splitting the illumination light into a plurality of beams by using an optical element having a plurality of optical surfaces;

condensing the plurality of the beams from the plurality of the optical surfaces by using a first optical system, the first optical system refocusing the plurality of beams split by the optical element such that first paths of the plurality of beams prior to entering the first optical system are different from second paths of the plurality of beams after exiting the first optical system, and the first optical system further guiding the plurality of beams to a predetermined plane;

giving an angle distribution of the light from a spatial light modulator arranged on the predetermined plane by using the spatial light modulator having a plurality of reflecting optical elements each of which has a movable reflection surface arranged to receive a respective beam of the plurality of beams traversing the second paths;

distributing a plurality of light beams from the movable reflection surface of each of the reflecting optical elements at a pupil position of an illumination optical system or a position optically conjugate with the pupil position; and

forming a spatial light distribution at the pupil position or the position optically conjugate with the pupil position on the basis of the plurality of light beams.

15. A device manufacturing method comprising:

illuminating a pattern with illumination light from a light source by using the illumination method according to claim 14;

exposing a photosensitive substrate with light from the pattern;

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

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