Spatial light modulator unit, illumination optical system, exposure device, and device manufacturing method

• US 9,817,229 B2
• Filed: 04/21/2016
• Issued: 11/14/2017
• Est. Priority Date: 12/23/2009
• Status: Active Grant

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: Tanitsu, Osamu
• Primary Examiner(s): ASFAW, MESFIN T
• Application Number:
  US15/134,812
• Publication Number:
  US 20160231558A1
• Time in Patent Office: 572 Days
• 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: 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 7/70191 Optical correction elements, filters or phase plates for controlling intensity, wavelength, polarisation, phase or the like

Abstract

According to one embodiment, a spatial light modulator unit is used in the illumination optical system for illuminating an illumination target surface with light from a light source and comprises: a spatial light modulator with a plurality of optical elements arrayed in a predetermined plane and controlled individually; a spatial light modulation element which applies spatial light modulation to the incident light from the light source and which makes rays of intensity levels according to positions of the respective optical elements, incident on the plurality of optical elements; and a control unit which individually controls the plurality of optical elements on the basis of information about the intensity levels of the rays incident on the respective optical elements.

Claims

1. An illumination optical apparatus which illuminates an object with illumination light, the illumination optical apparatus comprising:

an optical integrator which is disposed in an optical path of the illumination light;

a spatial light modulator which includes a plurality of optical elements arranged along a predetermined plane and disposed in the optical path on an incidence side of the optical integrator, the spatial light modulator forming a pupil intensity distribution of the illumination light, traveling via the optical integrator, on an illumination pupil of the illumination optical apparatus by driving the plurality of optical elements;

a lens element which is disposed in the optical path on an incidence side of the spatial light modulator; and

a light intensity modulator which is disposed in the optical path on an incidence side of the lens element, the light intensity modulator setting a light intensity distribution of the illumination light, traveling via the lens element, on the plurality of optical elements by modulating an intensity of the illumination light variably.

2. The illumination optical apparatus according to claim 1, wherein the light intensity modulator modulates the intensity of the illumination light so that the illumination light includes a nonuniform intensity distribution on the plurality of optical elements.

3. The illumination optical apparatus according to claim 2, wherein the light intensity modulator sets the light intensity distribution of the illumination light so that the intensity of the illumination light on the plurality of the optical elements discretely varies with respect to a direction along the predetermined plane on the basis of locations of the plurality of the optical elements.

4. The illumination optical apparatus according to claim 2, wherein the light intensity modulator sets the light intensity distribution of the illumination light so that the intensity of the illumination light on the plurality of the optical elements continuously varies with respect to a direction along the predetermined plane.

5. The illumination optical apparatus according to claim 1, wherein the light intensity modulator includes a plurality of mirror elements arranged along a cross section of the illumination light, a posture of each of the plurality of mirror elements being controlled individually.

6. The illumination optical apparatus according to claim 1, wherein the light intensity modulator includes a filter with a predetermined reflectance distribution or a predetermined transmittance distribution with respect, to a direction along a cross section of the illumination light.

7. The illumination optical apparatus according to claim 1, wherein the light intensity modulator includes a diffractive optical element which diffracts the illumination light.

8. The illumination optical apparatus according to claim 1, wherein the light intensity modulator includes a first modulator and a second modulator of which features are different from each other, and modulates the intensity of the illumination light by disposing the first modulator and the second modulator interchangeably on the optical path.

9. The illumination optical apparatus according to claim 1, wherein the spatial light modulator includes a driving control unit which controls a drive of the plurality of the optical elements on the basis of information with respect to the light intensity distribution of the illumination light on the plurality of the optical elements.

10. The illumination optical apparatus according to claim 1, wherein the spatial light modulator includes a plurality of mirror elements arranged along a cross section of the illumination light, a posture of each of the plurality of mirror elements being controlled individually.

11. The illumination optical apparatus according to claim 1, wherein the lens element includes a Fourier transform optical system which makes first and second positions on the optical path a Fourier transform relationship each other, the first position being a position at which the light intensity modulator is arranged, the second position being a position at which the spatial light modulator is arranged.

12. An exposure apparatus for exposing a substrate with illumination light, comprising:

the illumination optical apparatus as set forth in claim 1 which illuminates a pattern formed on an object; and

a projection optical system which projects an image of the pattern, which is illuminated by the illumination optical apparatus, onto a substrate held on a stage.

13. The exposure apparatus according to claim 12, further including a liquid immersion apparatus which fills a space between the projection optical system and the substrate with liquid, the space including an optical axis between the projection optical system and the substrate.

14. A device manufacturing method for forming a device on a substrate,

comprising:

performing exposure of the substrate, using the exposure apparatus as set forth in claim 12; and

developing the substrate exposed by the exposure apparatus.

15. An exposure method for exposing a substrate, comprising:

holding the substrate on a stage;

illuminating a pattern formed on an object by the illumination optical apparatus as set forth in claim 1; and

projecting an image of the pattern, which is illuminated by the illumination optical apparatus, onto the substrate held on the stage by a projection optical system.

16. The exposure method according to claim 15, further including filling a space between the projection optical system and the substrate with liquid, the space including an optical path between the projection optical system and the substrate.