SPATIAL LIGHT MODULATION UNIT, ILLUMINATION APPARATUS, EXPOSURE APPARATUS, AND DEVICE MANUFACTURING METHOD

• US 20090091730A1
• Filed: 09/10/2008
• Published: 04/09/2009
• Est. Priority Date: 10/03/2007
• Status: Abandoned Application

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: TANAKA, Hirohisa
• Application Number:
  US12/208,155
• Publication Number:
  US 20090091730A1
• Time in Patent Office: Days
• US Class Current: 355/67
• 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 7/70291 Addressable masks, e.g. spatial light modulators [SLMs], digital micro-mirror devices [DMDs] or liquid crystal display [LCD] patterning devices

Abstract

A spatial light modulation unit can be arranged in an optical system and can be arranged along an optical axis of the optical system. The spatial light modulation unit includes a first folding surface which folds light incident in parallel with the optical axis of the optical system; a reflective spatial light modulator which folds the light folded on the first folding surface; and a second folding surface which folds the light folded on the spatial light modulator, to emit the light into the optical system. The spatial light modulator applies spatial modulation to the light, according to a position where the light folded on the first folding surface is incident to the spatial light modulator.

Claims

1. A spatial light modulation unit which can be arranged in an optical system and which can be arranged along an optical axis of the optical system, the spatial light modulation unit comprising:

a first folding surface to fold light incident in parallel with the optical axis of the optical system;

a reflective spatial light modulator to reflect the light folded on the first folding surface; and

a second folding surface to fold the light reflected on the spatial light modulator, and to send forth the light into the optical system;

wherein the spatial light modulator applies spatial modulation to the light, according to a position where the light folded on the first folding surface is incident to the spatial light modulator.

2. The spatial light modulation unit according to claim 1, wherein the second folding surface includes a reflecting surface.

3. The spatial light modulation unit according to claim 2, wherein the first folding surface includes a reflecting surface.

4. The spatial light modulation unit according to claim 3, wherein the first and second folding surfaces include their respective internal reflecting surfaces.

5. The spatial light modulation unit according to claim 4, wherein the first and second reflecting surfaces are reflecting surfaces of a prism and wherein the spatial light modulator is attached integrally to the prism.

6. The spatial light modulation unit according to claim 4, wherein an air-equivalent length from a position of incidence to the prism to a exiting position from the prism is equal to an air-equivalent length from a position corresponding to the position of incidence to a position corresponding to the exiting position in a case where the prism is arranged outside the optical system.

7. The spatial light modulation unit according to claim 1, wherein the spatial light modulator is relatively movable relative to the first and second folding surfaces, in a direction along the optical axis of the optical system.

8. The spatial light modulation unit according to claim 3, wherein the first and second folding surfaces include their respective surface-reflecting surfaces.

9. The spatial light modulation unit according to claim 6, wherein the first and second folding surfaces are a pair of reflecting surfaces provided at a predetermined angle on a reflecting member.

10. The spatial light modulation unit according to claim 9, wherein the reflecting member and the spatial light modulator are arranged in a positional relation that can be relatively changed in a direction intersecting with the optical axis of the optical system.

11. The spatial light modulation unit according to claim 1, wherein the first and second folding surfaces and the spatial light modulator are arranged in a positional relation that can be relatively changed in a direction intersecting with the optical axis of the optical system.

12. The spatial light modulation unit according to claim 1, wherein the spatial light modulator includes a plurality of reflecting elements arranged two-dimensionally, and

wherein the plurality of reflecting elements can be controlled independently of each other.

13. The spatial light modulation unit according to claim 12, wherein each of the plurality of reflecting elements of the spatial light modulator includes a reflecting surface, and

wherein inclinations of the reflecting surfaces of the reflecting elements can be controlled independently.

14. The spatial light modulation unit according to claim 13, wherein the spatial light modulator can modulate the light so that the light folded on the second folding surface to be emitted into the optical system becomes parallel to the incident light to the first folding surface.

18. An illumination apparatus which illuminates a first surface with light supplied from a light source, the illumination apparatus comprising:

the spatial light modulation unit as set forth in claim 1.

19. The illumination apparatus according to claim 18, further comprising a diffractive optical element to form a desired pupil luminance distribution,

wherein the spatial light modulator can be arranged at a position conjugate with the diffractive optical element.

20. The illumination apparatus according to claim 18, further comprising a diffractive optical element which forms a desired pupil luminance distribution and which can be installed on a predetermined installation surface,

wherein the spatial light modulator can be arranged at a position optically equivalent to the predetermined installation surface.

21. The illumination apparatus according to claim 20, wherein the diffractive optical element can be inserted into or retracted from an optical path of the illumination apparatus.

36. An exposure apparatus which projects an image of a first surface onto a second surface, the exposure apparatus comprising:

the illumination apparatus as set forth in claim 18, which illuminates the first surface; and

a projection optical system which forms the image of the first surface on the second surface, based on light from an illumination region formed on the first surface by the illumination apparatus.

39. An exposure apparatus which projects an image of a first surface onto a second surface, the exposure apparatus comprising:

an illumination apparatus to illuminate the first surface;

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

a projection optical system which forms the image of the first surface on the second surface, based on light from an illumination region formed on the first surface by the illumination apparatus;

wherein the spatial light modulator of the spatial light modulation unit is arranged on the first surface.

40. A device manufacturing method comprising:

preparing a photosensitive substrate;

arranging the photosensitive substrate on the second surface in the exposure apparatus as set forth in claim 39, and projecting an image of a predetermined pattern located on the first surface, onto the photosensitive substrate to effect exposure thereof;

developing the photosensitive substrate onto which the image of the pattern includes been projected, to form a mask layer in 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.

43. An illumination apparatus which illuminates a first surface with light supplied from a light source, the illumination apparatus comprising:

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

a diffractive optical element which forms a first pupil luminance distribution with light not passing via the spatial light modulator of the spatial light modulation unit;

wherein a second pupil luminance distribution overlapping at least in part with the first pupil luminance distribution is formed with light from the spatial light modulator of the spatial light modulation unit.

15. A spatial light modulation unit which can be arranged in an optical system and which can be arranged along an optical axis of the optical system, the spatial light modulation unit comprising:

a first reflecting surface obliquely arranged relative to the optical axis of the optical system;

a second reflecting surface obliquely arranged relative to the optical axis of the optical system; and

a spatial light modulator provided so that it can be arranged in an optical path between the first reflecting surface and the second reflecting surface;

wherein the spatial light modulator applies spatial modulation to the light, according to a position in the spatial light modulator where the light is incident to the spatial light modulator.

16. The spatial light modulation unit according to claim 15, wherein the first reflecting surface is located on a first plane, and

wherein the second reflecting surface is located on a second plane intersecting with the first plane.

17. The spatial light modulation unit according to claim 16, wherein a ridge line made by the first and second planes is located on the spatial light modulator side with respect to the first and second reflecting surfaces and wherein an angle between the first and second reflecting surfaces is an obtuse angle.

22. An illumination apparatus which illuminates a first surface with light supplied from a light source, the illumination apparatus comprising:

the spatial light modulation unit as set forth in claim 15.

23. The illumination apparatus according to claim 22, further comprising a diffractive optical element to form a desired pupil luminance distribution,

wherein the spatial light modulator can be arranged at a position conjugate with the diffractive optical element.

24. The illumination apparatus according to claim 22, further comprising a diffractive optical element which forms a desired pupil luminance distribution and which can be installed on a predetermined installation surface,

wherein the spatial light modulator can be arranged at a position optically equivalent to the predetermined installation surface.

25. The illumination apparatus according to claim 23, wherein the diffractive optical element can be inserted into or retracted from an optical path of the illumination apparatus.

37. An exposure apparatus which projects an image of a first surface onto a second surface, the exposure apparatus comprising:

the illumination apparatus as set forth in claim 22, which illuminates the first surface; and

a projection optical system which forms the image of the first surface on the second surface, based on light from an illumination region formed on the first surface by the illumination apparatus.

41. An exposure apparatus which projects an image of a first surface onto a second surface, the exposure apparatus comprising:

an illumination apparatus to illuminate the first surface;

the spatial light modulation unit as set forth in claim 15; and

a projection optical system which forms the image of the first surface on the second surface, based on light from an illumination region formed on the first surface by the illumination apparatus;

wherein the spatial light modulator of the spatial light modulation unit is arranged on the first surface.

42. A device manufacturing method comprising:

preparing a photosensitive substrate;

arranging the photosensitive substrate on the second surface in the exposure apparatus as set forth in claim 41, and projecting an image of a predetermined pattern located on the first surface, onto the photosensitive substrate to effect exposure thereof;

developing the photosensitive substrate onto which the image of the pattern includes been projected, to form a mask layer in 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.

44. An illumination apparatus which illuminates a first surface with light supplied from a light source, the illumination apparatus comprising:

the spatial light modulation unit as set forth in claim 15; and

a diffractive optical element which forms a first pupil luminance distribution with light not passing via the spatial light modulator of the spatial light modulation unit;

wherein a second pupil luminance distribution overlapping at least in part with the first pupil luminance distribution is formed with light from the spatial light modulator of the spatial light modulation unit.

26. An illumination apparatus which illuminates an illumination target surface on the basis of light from a light source, the illumination apparatus comprising:

a spatial light modulator including a plurality of optical elements arranged two-dimensionally and controlled individually;

a diffractive optical element which can be arranged in the illumination apparatus;

a first optical path in which the spatial light modulator can be arranged at a first position thereof;

a second optical path in which the diffractive optical element can be arranged at a second position thereof;

a third optical path which is an optical path between the light source and the first optical path and optical path between the light source and the second optical path; and

a fourth optical path which is an optical path between the first optical path and the illumination target surface and optical path between the second optical path and the illumination target surface;

wherein the first optical path and the second optical path are switchable from one to the other and wherein an optical axis at an exit of the third optical path and an optical axis at an entrance of the fourth optical path are coaxial.

27. The illumination apparatus according to claim 26, comprising:

a first optical surface which directs light from the third optical path toward the spatial light modulator; and

a second optical surface which directs light having passed via the spatial light modulator, toward the fourth optical path.

28. The illumination apparatus according to claim 27, wherein the first optical surface and the second optical surface can be inserted into or retracted from an optical path of the illumination apparatus.

29. The illumination apparatus according to claim 28, wherein the first and second optical surfaces can be integrally inserted into or retracted from the optical path of the illumination apparatus.

30. The illumination apparatus according to claim 26, wherein the spatial light modulator can be inserted into or retracted from an optical path of the illumination apparatus.

31. The illumination apparatus according to claim 26, wherein the spatial light modulator is fixed at a predetermined position.

32. The illumination apparatus according to claim 26, wherein the first optical path and the second optical path are simultaneously used.

33. The illumination apparatus according to claim 27, wherein the first and second optical surfaces include their respective reflecting surfaces.

34. The illumination apparatus according to claim 26, wherein the spatial light modulator includes a plurality of reflecting elements arranged two-dimensionally, and

wherein the plurality of reflecting elements can be controlled independently of each other.

35. The illumination apparatus according to claim 34, wherein each of the reflecting elements of the spatial light modulator includes a reflecting surface, and

wherein inclinations of the reflecting surfaces of the reflecting elements can be controlled independently.

38. An exposure apparatus which projects an image of a first surface onto a second surface, the exposure apparatus comprising:

the illumination apparatus as set forth in claim 26, which illuminates the first surface; and

a projection optical system which forms the image of the first surface on the second surface, based on light from an illumination region formed on the first surface by the illumination apparatus.

45. An illumination apparatus which illuminates a first surface with light supplied from a light source, the illumination apparatus comprising:

a spatial light modulation unit comprising a spatial light modulator which applies spatial modulation to the light according to a position of incidence thereof; and

a diffractive optical element which forms a first pupil luminance distribution with light not passing via the spatial light modulator of the spatial light modulation unit;

wherein a second pupil luminance distribution overlapping at least in part with the first pupil luminance distribution is formed with light from the spatial light modulator of the spatial light modulation unit.

46. The illumination apparatus according to claim 45, wherein the spatial light modulator includes a plurality of reflecting elements arranged two-dimensionally, and

wherein the plurality of reflecting elements can be controlled independently of each other.

47. The illumination apparatus according to claim 46, wherein each of the reflecting elements of the spatial light modulator includes a reflecting surface, and

wherein inclinations of the reflecting surfaces of the reflecting elements can be controlled independently.

48. An exposure apparatus which projects an image of a first surface onto a second surface, the exposure apparatus comprising:

the illumination apparatus as set forth in claim 45, which illuminates the first surface; and

a projection optical system which forms the image of the first surface on the second surface, based on light from an illumination region formed on the first surface by the illumination apparatus.

49. A device manufacturing method comprising:

preparing a photosensitive substrate;

arranging the photosensitive substrate on the second surface in the exposure apparatus as set forth in claim 48, and projecting an image of a predetermined pattern located on the first surface, onto the photosensitive substrate to effect exposure thereof;

developing the photosensitive substrate onto which the image of the pattern includes been projected, to form a mask layer in 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.