Illumination optical system, exposure apparatus, and exposure method

• US 20060055834A1
• Filed: 05/31/2005
• Published: 03/16/2006
• Est. Priority Date: 12/03/2002
• Status: Active Grant

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: Tanaka, Hirohisa, Tanitsu, Osamu, Muramatsu, Kenichi, Matsuyama, Tomoyuki, Komine, Norio, Kudo, Takehito, Nishinaga, Hisashi
• Granted Patent: US 7,423,731 B2
• Time in Patent Office: Days
• US Class Current: 349/5
• CPC Class Codes: G03B 27/42 for automatic sequential copying of the same original G03B27/34, G03B27/53 take precedence
• CPC Class Codes: G03F 7/70091 Illumination settings, i.e. intensity distribution in the pupil plane or angular distribution in the field plane; On-axis or off-axis settings, e.g. annular, dipole or quadrupole settings; Partial coherence control, i.e. sigma or numerical aperture [NA]
• CPC Class Codes: G03F 7/70566 Polarisation control

Abstract

An illumination optical system for, when installed in an exposure system, realizing a suitable illumination condition by varying the polarized state of the illumination light according to the pattern characteristics of the mask while suppressing the loss of the intensity of the light. The illumination optical system has a light source unit for supplying a linearly polarized light for illuminating surfaces to be illuminated therewith, and a polarized state changing device for changing the polarized state of the illuminating light from a predetermined polarized state to a nonpolarized state and vice versa. The polarized state changing device is arranged in the optical path between the light source unit and the surfaces to be illuminated. The polarized state changing device can be removed from the illumination optical path and has a depolarizer for selectively depolarizing the incident linearly polarized light.

Claims

1. An illumination optical system that includes a light source that provides linearly polarized light and illuminates an illuminated surface with the light from the light source, comprising:

a polarized state switching device positioned in a light path between the light source and the illuminated surface, the polarized state switching device switches a polarized state of the light that illuminates the illuminated surface between a predetermined polarized state and a nonpolarized state while controlling a loss of light amount.

2. The illumination optical system of claim 1, wherein the polarized state switching device varies a polarization plane of the linearly polarized light if the predetermined polarized state is a linearly polarized state.

3. The illumination optical system of claim 2, wherein the polarized state switching device includes a phase member for selectively changing a polarization plane of the incident linearly polarized light.

4. The illumination optical system of claim 3, wherein the phase member includes a half-wave plate having a crystal optic axis that is rotatable about an optical axis of the illumination optical system.

5. The illumination optical system of claim 1, wherein the polarized state switching device comprises a depolarizer that unpolarizes the incident linearly polarized light, the depolarizer being insertable into and removable from an illumination light path.

6. The illumination optical system of claim 1, wherein the polarized state switching device comprises a depolarizer that unpolarizes the incident linearly polarized light, and

when switching the polarized state of the light that illuminates the illuminated surface, light in a polarized state that has not been unpolarized by the depolarizer is directed to the depolarizer.

7. The illumination optical system of claim 6, wherein the depolarizer comprises a crystal prism having a crystal optic axis extending in a predetermined direction.

8. The illumination optical system of claim 7, wherein when switching the polarized state of the light that illuminates the illuminated surface, the linearly polarized light that has a polarization plane in a direction of the crystal optic axis of the depolarizer is directed to the depolarizer.

9. The illumination optical system of claim 5, wherein the depolarizer comprises a crystal prism having a crystal optic axis that is rotatable about an optical axis of the illumination optical system.

10. The illumination optical system of claim 5, wherein the depolarizer includes a polarized beam splitter and a reflection system that returns light reflected by the polarized beam splitter back to the polarized beam splitter by reflecting the light plural times in a plane such that a light path of light that is transmitted through the polarized beam splitter and a light path of the light reflected by the polarized beam splitter substantially match each other, the polarized beam splitter and the reflection system being integrally rotatable about an optical axis of the illumination optical system.

11. The illumination optical system of claim 5, wherein the depolarizer includes a polarized beam splitter and a reflection system that returns light reflected by the polarized beam splitter back to the polarized beam splitter by reflecting the light plural times in a plane such that a light path of light that is transmitted through the polarized beam splitter and a light path of the light reflected by the polarized beam splitter substantially match each other, the polarized beam splitter and the reflection system being integrally insertable into and removable from the illumination light path.

12. The illumination optical system of claim 3, wherein the polarized state switching device further includes a second phase member for converting incident elliptically polarized light into linearly polarized light.

13. The illumination optical system of claim 12, wherein the second phase member includes a quarter-wave plate having a crystal optic axis that is rotatable about an optical axis of the illumination optical system.

14. The illumination optical system of claim 1, wherein a light transmissive member is positioned in the light path between the light source and the polarized state switching device and is formed by a cubic system crystal material, the light transmissive member being configured such that a traveling direction of the light becomes closer to a crystal orientation <

111>

or <

100>

than a crystal orientation <

110>

.

15. The illumination optical system of claim 14, wherein a light transmissive member is positioned in the light path between the polarized state switching device and the illuminated surface and is formed by a cubic system crystal material, the light transmissive member being configured such that a traveling direction of the light becomes closer to a crystal orientation <

111>

or <

100>

than to a crystal orientation <

110>

.

16. The illumination optical system of claim 14, wherein the light transmissive member includes an optical member fixedly positioned in the light path, and

an optical axis of the optical member is configured to substantially match the crystal orientation <

111>

or <

100>

.

17. The illumination optical system of claim 14, wherein the light transmissive member includes a rectangular prism as a rear surface reflection mirror,

an incident surface and an exit surface of the rectangular prism are configured to substantially match a crystal plane {1 00}, and

a reflection surface of the rectangular prism is configured to substantially match a crystal plane {1 10}.

18. The illumination optical system of claim 14, wherein the light transmissive member includes a plane parallel plate for moving light entering along the optical axis in parallel, the light transmissive member being provided in the light path and inclinable with respect to the optical axis, and

the optical axis of the plane parallel plate substantially matches the crystal orientation <

100>

.

19. The illumination optical system of claim 1, further comprising:

an illumination pupil distribution forming device that forms a predetermined light intensity distribution on or adjacent to a pupil plane of the illumination optical system;

a changing device that changes at least one of a shape and a size of the predetermined light intensity distribution; and

a light direction optical system that directs a light beam having the predetermined light intensity distribution to the illuminated surface.

20. The illumination optical system of claim 19, wherein the polarized state switching device changes a polarized state of the light that illuminates the illuminated surface in accordance with the change in at least one of the shape and the size of the predetermined light intensity distribution.

21. The illumination optical system of claim 20, wherein the polarized state switching device switches the polarized state of the light that illuminates the illuminated surface between the linearly polarized state and the nonpolarized state in accordance with the change in at least one of the shape and the size of the predetermined light intensity distribution.

22. The illumination optical system of claim 1, wherein an S1 component of a Stokes parameter of the light satisfies the below condition in the predetermined polarized state:

0.6<

|S1|

23. The illumination optical system of claim 1, wherein S1 and S2 components of a Stokes parameter of the light satisfy the below conditions in the nonpolarized state:

|S1|≦

0.1
|S2|≦

0.1

24. The illumination optical system of claim 1, further comprising a polarized state fluctuation correcting device that corrects fluctuations of the polarized state on the illuminated surface, the polarized state fluctuation correcting device being positioned in the light path between the light source and the illuminated surface.

25. The illumination optical system of claim 24, wherein the polarized state fluctuation correcting device comprises a polarization monitor positioned in the light path between the polarized state switching device and the illuminated surface to detect the polarized state of the light, and a controller that controls the polarized state switching device in response to an output from the polarization monitor.

26. The illumination optical system of claim 25, wherein

the polarized state switching device comprises a half-wave plate having a crystal optic axis that is rotatable about the optical axis of the illumination optical system, and a quarter-wave plate having a crystal optic axis that is rotatable about the optical axis of the illumination optical system, and

in response to changes in detection results obtained from the polarization monitor when respectively changing the crystal optic axes of the quarter-wave plate and the half-wave plate, the controller adjusts an angular position of the crystal optic axis of the quarter-wave plate to a predetermined position for converting incident elliptically polarized light into linearly polarized light and an angular position of the crystal optic axis of the half-wave plate to a predetermined position for converting incident linearly polarized light into linearly polarized light that has a polarization plane in a predetermined direction.

27. The illumination optical system of claim 26, wherein the controller adjusts the angular position of the crystal optic axis of the quarter-wave plate to a first angular position, at which a contrast for changes in an S1 component of the Stokes parameter in the detection result becomes substantially maximum when the crystal optic axis of the quarter-wave plate is changed, and the angular position of the crystal optic axis of the half-wave plate to a second angular position, at which the S1 component of the Stokes parameter in the detection result becomes substantially maximum or substantially minimum when the crystal optic axis of the half-wave plate is changed while the crystal optic axis of the quarter-wave plate is set at the first angular position.

28. The illumination optical system of claim 25, wherein the polarization monitor is positioned in the light path between the polarized state switching device and the illuminated surface and includes a beam splitter that extracts from the light path reflected light or transmitted light in a polarized state different from the polarized state of the incident light, and a light intensity detector that detects an intensity of the reflected light or the transmitted light extracted by the beam splitter, and

the polarized state of the incident light to the beam splitter is detected based on an output of the light intensity detector.

29. The illumination optical system of claim 28, wherein the beam splitter has reflectivity or transmissivity, in which an intensity Ip for P-polarized light and an intensity Is for S-polarized light included in the reflected light or the transmitted light satisfy a condition that an intensity ratio Ip/Is is less than ½

(Ip/Is<

½

) or more than 2 (Ip/Is>

2).

30. The illumination optical system of claim 1, further comprising an illumination pupil distribution forming device that forms a predetermined light intensity distribution on or adjacent to a pupil plane of the illumination optical system,

wherein the illumination pupil distribution forming device forms two areas having a high light intensity distribution that are spaced along a direction of the pupil plane or a surface adjacent thereto that corresponds to a predetermined first direction on the illuminated surface, and

the polarized state switching device sets the polarized state of the light that illuminates the illuminated surface from the two areas having a high light intensity distribution to the linearly polarized state that has a polarization plane in a direction substantially orthogonal to the predetermined first direction.

31. The illumination optical system of claim 30, wherein the two areas having a high light intensity distribution are formed symmetrically about the optical axis of the illumination optical system, and

a value σ

o defined by a ratio φ

o/φ

p satisfies the following condition;

0.7≦

σ

o

where φ

o is a diameter of a circle about the optical axis that circumscribes the two areas having a high light intensity distribution, and φ

p is a diameter of the pupil plane.

32. The illumination optical system of claim 30, wherein the two areas having a high light intensity distribution are formed symmetrically about the optical axis of the illumination optical system, and

a value σ

o defined by a ratio φ

o/φ

p and σ

i defined by a ratio φ

i/φ

p satisfy the following condition;

0.5≦

σ

i/σ

o

where φ

o is a diameter of a circle about the optical axis that circumscribes the two areas having a high light intensity distribution, φ

p is a diameter of the pupil plane, and φ

i is a diameter of a circle about the optical axis that inscribes the two areas having a high light intensity distribution.

33. An exposure apparatus, comprising the illumination optical system of claim 1.

34. The exposure apparatus of claim 33, further comprising:

a projection optical system positioned in the light path between a first plane at which the mask is positioned, and a second plane at which the photosensitive substrate is positioned, the projection optical system forming an image of a pattern on the mask onto the second plane;

a pupil intensity distribution forming device that forms a predetermined light intensity distribution at a position conjugate to a pupil of the projection optical system or a position adjacent thereto; and

a pupil intensity distribution changing device that changes at least one of a shape and a size of the predetermined light intensity distribution.

35. The exposure apparatus of claim 34, further comprising a polarized state changing device that is positioned in the light path between the light source and the illuminated surface and changes the polarized state of the light that illuminates the illuminated surface, wherein

the pupil intensity distribution changing device changes at least one of the shape and the size of the predetermined light intensity distribution in accordance with pattern characteristics of the mask, and

the polarized state changing device changes the polarized state of the light that illuminates the illuminated surface in accordance with at least one of the shape and the size of the predetermined light intensity distribution.

36. The exposure apparatus of claim 35, wherein

the polarized state changing device comprises the polarized state switching device that switches the polarized state of the light that illuminates the illuminated surface between a predetermined polarized state and a nonpolarized state, and

the polarized state switching device switches between the predetermined polarized state and the nonpolarized state in accordance with a change in at least one of the shape and the size of the predetermined light intensity distribution.

37. The exposure apparatus of claim 35, wherein

the pupil intensity distribution forming device forms two areas having a high light intensity distribution that are spaced away from each other along a pitch direction of a line-and-space pattern formed on the mask, and

the polarized state changing device sets the polarized state of the light that illuminates the illuminated surface from the two areas having a high light intensity distribution to a linearly polarized state that has a polarization plane in a direction orthogonal to the pitch direction.

38. The exposure apparatus of claim 37, wherein the two areas having a high light intensity distribution are formed symmetrically about the optical axis of the illumination optical system, and

a value σ

o defined by a ratio φ

o/φ

p satisfies the following condition;

0.7≦

σ

o

where φ

o is a diameter of a circle about the optical axis that circumscribes the two areas having a high light intensity distribution, and φ

p is a diameter of the pupil plane.

39. The exposure apparatus of claim 37, wherein the two areas having a high light intensity distribution are formed symmetrically about the optical axis of the illumination optical system, and

a value σ

o defined by a ratio φ

o/φ

p and σ

i defined by a ratio φ

i/φ

p satisfy the following condition;

0.5<

σ

o/σ

i

where φ

o is a diameter of a circle about the optical axis that circumscribes the two areas having a high light intensity distribution, φ

p is a diameter of the pupil plane, and φ

i is a diameter of a circle about the optical axis that inscribes the two areas having a high light intensity distribution.

40. The exposure apparatus of claim 35, wherein

the pupil intensity distribution forming device forms one area having a high light intensity distribution substantially about the optical axis of the illumination optical system, and

the polarized state changing device sets the polarized state of the light that illuminates the illuminated surface from the one area having a high light intensity distribution to the linearly polarized state that has a polarization plane in a direction substantially orthogonal to the pitch direction of the line-and-space pattern formed on a phase shift mask as the mask.

41. The exposure apparatus of claim 40, wherein a value σ

that is defined by a ratio φ

o/φ

p satisfies the following condition;

σ

≧

0.4

where φ

is a size of the one area having a high light intensity distribution, and φ

p is a diameter of the pupil plane.

42. An exposure method, comprising:

an illumination step that illuminates a mask through the illumination optical system of claim 1;

and

an exposure step that exposes an image of a pattern on the mask onto the photosensitive substrate positioned on the illuminated surface.

43. The exposure method of claim 42, further comprising:

a projection process for forming the image of the pattern on the mask using a projection optical system;

a pupil intensity distribution forming step that forms a predetermined light intensity distribution at a position conjugate to a pupil of the projection optical system or a position adjacent thereto; and

a pupil intensity distribution changing step that changes at least one of a shape or a size of the predetermined light intensity distribution.

44. The exposure method of claim 43, wherein the pupil intensity distribution changing step changes at least one of the shape and the size of the predetermined light intensity distribution in accordance with pattern characteristics of the mask;

the exposure method further comprises a polarized state changing step that changes a polarized state of the light that illuminates the illuminated surface in accordance with a change in the at least one of the shape and the size of the predetermined light intensity distribution.

45. The exposure method of claim 44, wherein the pupil intensity distribution forming step forms two areas having a high light intensity distribution spaced away from each other along a pitch direction of a line-and-space pattern formed on the mask, the exposure method further comprising a step of setting the polarized state of the light that illuminates the illuminated surface from the two areas having a high light intensity distribution to a linearly polarized state that has a polarization plane in a direction substantially orthogonal to the pitch direction.

46. The exposure method of claim 45, wherein

the two areas having a high light intensity distribution are formed symmetrically about the optical axis of the illumination optical system, and

a value σ

o defined by a ratio φ

o/φ

p satisfies the following condition;

0.7≦

φ

o

where φ

o is a diameter of a circle about the optical axis that circumscribes the two areas having a high light intensity distribution, and φ

p is a diameter of the pupil plane.

47. The exposure method of claim 45, wherein

the two areas having a high light intensity distribution are formed symmetrically about the optical axis of the illumination optical system, and

a value σ

o defined by a ratio φ

o/φ

p and σ

i defined by a ratio φ

i/φ

p satisfy the following condition;

0.5≦

σ

i/σ

o

where φ

o is a diameter of a circle about the optical axis that circumscribes the two areas having a high light intensity distribution, φ

p is a diameter of the pupil plane, and φ

i is a diameter of a circle about the optical axis that inscribes the two areas having a high light intensity distribution.

48. An illumination optical system that illuminates an illuminated surface with light having a predetermined polarized state supplied from a light source, comprising:

a light directing device that directs the light from the light source to the illuminated surface, the light directing device being positioned in a light path between the light source and the illuminated surface; and

a polarized state fluctuation correcting device that corrects fluctuations in the polarized state on the illuminated surface, the polarized state fluctuation correcting device being positioned in the light path between the light source and the illuminated surface.

49. The illumination optical system of claim 48, wherein the polarized state fluctuation correcting device comprises:

a polarized state adjusting device that adjust the polarized state on the illuminated surface, the polarized state adjusting device being positioned in the light path between the light source and the illuminated surface;

a polarization monitor that detects the polarized state of the light, the polarization monitor being positioned in the light path between the light source and the illuminated surface; and

a controller that controls the polarized state adjusting device in accordance with an output from the polarization monitor.

50. The illumination optical system of claim 49, wherein the polarized state adjusting device comprises an adjustable phase plate positioned in the light path between the light source and the polarization monitor.

51. The illumination optical system of claim 48, wherein the light directing device comprises an optical member having a characteristic that changes the polarized state of incident light that it ejects.

52. The illumination optical system of claim 51, wherein the optical member is formed by a crystal optical material.

53. The illumination optical system of claim 48, wherein the polarized state fluctuation correcting device corrects fluctuations in the polarized state on the illuminated surface, which originates in a light transmissive member in the light directing device.

54. The illumination optical system of claim 53, wherein the light transmissive member is formed by a crystal optical material.

55. The illumination optical system of claim 54, wherein the light transmissive member is formed by a cubic system crystal material and positioned in the light path between the light source and the illuminated surface, the light transmissive member being configured such that a traveling direction of the light becomes closer to a crystal orientation <

111>

or <

100>

than to a crystal orientation <

110>

.

56. The illumination optical system of claim 55, wherein

the polarized state fluctuation correcting device comprises a polarized state adjusting device that is positioned in the light path between the light source and the illuminated surface and that adjusts the polarized state on the illuminated surface, and

the light transmissive member is formed by a cubic system crystal material and is positioned in the light path between the light source and the polarized state adjusting device, the light transmissive member being configured such that a traveling direction of the light becomes closer to a crystal orientation <

111>

or <

100>

than to a crystal orientation <

110>

.

57. The illumination optical system of claim 55, wherein the light transmissive member includes an optical member fixedly positioned in the light path, and an optical axis of the optical member is configured to substantially match the crystal orientation <

111>

or <

100>

.

58. The illumination optical system of claim 55, wherein the light transmissive member includes a rectangular prism as a rear surface reflection mirror,

an incident surface and an exit surface of the rectangular prism are configured to substantially match a crystal plane {1 00}, and

a reflection surface of the rectangular prism is configured to substantially match a crystal plane {1 10}.

59. The illumination device of claim 55, wherein the light transmissive member includes a plane parallel plate for moving light entering along the optical axis in parallel, the light transmissive member being provided in the light path and inclinable with respect to the optical axis, and

the optical axis of the plane parallel plate is configured to substantially match the crystal orientation <

100>

.

60. The illumination optical system of claim 48, wherein the polarized state fluctuation correction device corrects time-lapse fluctuations of the polarized state on the illuminated surface.

61. An exposure apparatus, comprising the illumination optical system of claim 48.

62. The exposure apparatus of claim 61, further comprising:

a projection optical system positioned in the light path between a first plane at which the mask is positioned, and a second plane at which the photosensitive substrate is positioned, the projection optical system forming an image of a pattern on the mask onto the second plane;

a pupil intensity distribution forming device that forms a predetermined light intensity distribution at a position conjugate to a pupil of the projection optical system or a position adjacent thereto; and

a pupil intensity distribution changing device that changes at least one of a shape and a size of the predetermined light intensity distribution.

63. The exposure apparatus of claim 62, further comprising a polarized state changing device that is positioned in the light path between the light source and the illuminated surface and changes the polarized state of the light that illuminates the illuminated surface, wherein

the pupil intensity distribution changing device changes at least one of the shape and the size of the predetermined light intensity distribution in accordance with pattern characteristics of the mask, and

the polarized state changing device changes the polarized state of the light that illuminates the illuminated surface in accordance with at least one of the shape and the size of the predetermined light intensity distribution.

64. The exposure apparatus of claim 63, wherein

the polarized state changing device comprises a polarized state switching device that switches the polarized state of the light that illuminates the illuminated surface between a predetermined polarized state and a nonpolarized state, and

the polarized state switching device switches between the predetermined polarized state and the nonpolarized state in accordance with a change in at least one of the shape and the size of the predetermined light intensity distribution.

65. The exposure apparatus of claim 63, wherein

the pupil intensity distribution forming device forms two areas having a high light intensity distribution that are spaced away from each other along a pitch direction of a line-and-space pattern formed on the mask, and

the polarized state changing device sets the polarized state of the light that illuminates the illuminated surface from the two areas having a high light intensity distribution to a linearly polarized state that has a polarization plane in a direction orthogonal to the pitch direction.

66. The exposure apparatus of claim 65, wherein the two areas having a high light intensity distribution are formed symmetrically about the optical axis of the illumination optical system, and

a value σ

o defined by a ratio φ

o/φ

p satisfies the following condition;

0.7≦

σ

o

where φ

o is a diameter of a circle about the optical axis that circumscribes the two areas having a high light intensity distribution, and φ

p is a diameter of the pupil plane.

67. The exposure apparatus of claim 65, wherein the two areas having a high light intensity distribution are formed symmetrically about the optical axis of the illumination optical system, and

a value σ

o defined by a ratio φ

o/φ

p and σ

i defined by a ratio φ

i/φ

p satisfy the following condition;

0.5<

σ

o/σ

i

where φ

o is a diameter of a circle about the optical axis that circumscribes the two areas having a high light intensity distribution, φ

p is a diameter of the pupil plane, and φ

i is a diameter of a circle about the optical axis that inscribes the two areas having a high light intensity distribution.

68. The exposure apparatus of claim 63, wherein

the pupil intensity distribution forming device forms one area having a high light intensity distribution substantially about the optical axis of the illumination optical system, and

the polarized state changing device sets the polarized state of the light that illuminates the illuminated surface from the one area having a high light intensity distribution to the linearly polarized state that has a polarization plane in a direction substantially orthogonal to the pitch direction of the line-and-space pattern formed on a phase shift mask as the mask.

69. The exposure apparatus of claim 68, wherein a value σ

that is defined by a ratio φ

o/φ

p satisfies the following condition;

σ

≦

0.4

where φ

is a size of the one area having a high light intensity distribution, and φ

p is a diameter of the pupil plane.

70. An exposure method, comprising:

an illumination step that illuminates a mask through the illumination optical system of claim 48;

and

an exposure step that exposes an image of a pattern on the mask onto the photosensitive substrate positioned on the illuminated surface.

71. The exposure method of claim 70, further comprising:

a projection process for forming the image of the pattern on the mask using a projection optical system;

a pupil intensity distribution forming step that forms a predetermined light intensity distribution at a position conjugate to a pupil of the projection optical system or a position adjacent thereto; and

a pupil intensity distribution changing step that changes at least one of a shape or a size of the predetermined light intensity distribution.

72. The exposure method of claim 71, wherein the pupil intensity distribution changing step changes at least one of the shape and the size of the predetermined light intensity distribution in accordance with pattern characteristics of the mask;

the exposure method further comprises a polarized state changing step that changes a polarized state of the light that illuminates the illuminated surface in accordance with a change in the at least one of the shape and the size of the predetermined light intensity distribution.

73. The exposure method of claim 72, wherein the pupil intensity distribution forming step forms two areas having a high light intensity distribution spaced away from each other along a pitch direction of a line-and-space pattern formed on the mask, the exposure method further comprising a step of setting the polarized state of the light that illuminates the illuminated surface from the two areas having a high light intensity distribution to a linearly polarized state that has a polarization plane in a direction substantially orthogonal to the pitch direction.

74. The exposure method of claim 73, wherein

the two areas having a high light intensity distribution are formed symmetrically about the optical axis of the illumination optical system, and

a value σ

o defined by a ratio φ

o/φ

p satisfies the following condition;

0.7≦

σ

o

where φ

o is a diameter of a circle about the optical axis that circumscribes the two areas having a high light intensity distribution, and φ

p is a diameter of the pupil plane.

75. The exposure method of claim 73, wherein

the two areas having a high light intensity distribution are formed symmetrically about the optical axis of the illumination optical system, and

a value σ

o defined by a ratio φ

o/φ

p and σ

i defined by a ratio φ

i/φ

p satisfy the following condition;

0.5≦

σ

i/σ

o

where φ

o is a diameter of a circle about the optical axis that circumscribes the two areas having a high light intensity distribution, φ

p is a diameter of the pupil plane, and φ

i is a diameter of a circle about the optical axis that inscribes the two areas having a high light intensity distribution.

76. A method for adjusting an illumination optical system that illuminates an illuminated surface with light having a predetermined polarized state supplied from a light source, comprising:

a wavelength plate setting step that sets a quarter-wave plate in an illumination light path of the illumination optical system such that a crystal optic axis of the quarter-wave plate is set at a predetermined angular position, and sets a half-wave plate in the illumination light path such that a crystal optic axis of the half-wave plate is set at a predetermined angular positioned, wherein

based on a result of detection of the polarized state of the light in the light path between a polarized state switching device and the illuminated surface when the crystal optic axes of the quarter-wave plate and the half-wave plate are respectively changed, the wavelength plate setting step sets the crystal optic axis of the quarter-wave plate at a desired position for converting incident elliptically polarized light into linearly polarized light, and the crystal optic axis of the half-wave plate at a standard position for converting incident linearly polarized light into linearly polarized light that has a polarized plane in a predetermined direction.

77. The adjustment method of claim 76, wherein

the crystal optic axis of the quarter-wave plate is set at a first angular position, at which a contrast for changes in an S1 component of a Stokes parameter becomes substantially maximum in the detection result, and

the crystal optic axis of the half-wave plate is set at a second angular position, at which the S1 component of the Stokes parameter becomes substantially maximum or substantially minimum in the detection result while the crystal optic axis of the quarter-wave plate is set at the first angular position.

78. The adjustment method of claim 76, further comprising:

an illumination pupil forming step that forms a predetermined light intensity distribution on or adjacent to a pupil plane of the illumination optical system by the light from the light source,

an illumination pupil changing step that changes at least one of a shape and a size of the predetermined light intensity distribution, and

a wavelength plate resetting step that resets at least one of the crystal optic axes of the quarter-wave plate and the half-wave plate.

79. An exposure apparatus, comprising the illumination optical system adjusted by the adjustment method of claim 76.

80. The exposure apparatus of claim 79, further comprising:

a projection optical system positioned in the light path between a first plane at which the mask is positioned, and a second plane at which the photosensitive substrate is positioned, the projection optical system forming an image of a pattern on the mask onto the second plane;

a pupil intensity distribution forming device that forms a predetermined light intensity distribution at a position conjugate to a pupil of the projection optical system or a position adjacent thereto; and

a pupil intensity distribution changing device that changes at least one of a shape and a size of the predetermined light intensity distribution.

81. The exposure apparatus of claim 80, further comprising a polarized state changing device that is positioned in the light path between the light source and the illuminated surface and changes the polarized state of the light that illuminates the illuminated surface, wherein

the pupil intensity distribution changing device changes at least one of the shape and the size of the predetermined light intensity distribution in accordance with pattern characteristics of the mask, and

the polarized state changing device changes the polarized state of the light that illuminates the illuminated surface in accordance with at least one of the shape and the size of the predetermined light intensity distribution.

82. The exposure apparatus of claim 81, wherein

the polarized state changing device comprises a polarized state switching device that switches the polarized state of the light that illuminates the illuminated surface between a predetermined polarized state and a nonpolarized state, and

the polarized state switching device switches between the predetermined polarized state and the nonpolarized state in accordance with a change in at least one of the shape and the size of the predetermined light intensity distribution.

83. The exposure apparatus of claim 81, wherein

the pupil intensity distribution forming device forms two areas having a high light intensity distribution that are spaced away from each other along a pitch direction of a line-and-space pattern formed on the mask, and

the polarized state changing device sets the polarized state of the light that illuminates the illuminated surface from the two areas having a high light intensity distribution to a linearly polarized state that has a polarization plane in a direction orthogonal to the pitch direction.

84. The exposure apparatus of claim 83, wherein the two areas having a high light intensity distribution are formed symmetrically about the optical axis of the illumination optical system, and

a value σ

o defined by a ratio φ

o/φ

p satisfies the following condition;

0.7≦

σ

o

where φ

o is a diameter of a circle about the optical axis that circumscribes the two areas having a high light intensity distribution, and φ

p is a diameter of the pupil plane.

85. The exposure apparatus of claim 83, wherein the two areas having a high light intensity distribution are formed symmetrically about the optical axis of the illumination optical system, and

a value σ

o defined by a ratio φ

o/φ

p and σ

i defined by a ratio φ

i/φ

p satisfy the following condition;

0.5≦

σ

o/σ

i

where φ

o is a diameter of a circle about the optical axis that circumscribes the two areas having a high light intensity distribution, φ

p is a diameter of the pupil plane, and φ

i is a diameter of a circle about the optical axis that inscribes the two areas having a high light intensity distribution.

86. The exposure apparatus of claim 81, wherein

the pupil intensity distribution forming device forms one area having a high light intensity distribution substantially about the optical axis of the illumination optical system, and

the polarized state changing device sets the polarized state of the light that illuminates the illuminated surface from the one area having a high light intensity distribution to the linearly polarized state that has a polarization plane in a direction substantially orthogonal to the pitch direction of the line-and-space pattern formed on a phase shift mask as the mask.

87. The exposure apparatus of claim 86, wherein a value σ

that is defined by a ratio φ

o/φ

p satisfies the following condition;

σ

≦

0.4

where φ

is a size of the one area having a high light intensity distribution, and φ

p is a diameter of the pupil plane.

88. An exposure method, comprising:

an illumination step that illuminates a mask through the illumination optical system adjusted in accordance with the adjustment method of claim 76;

and

an exposure step that exposes an image of a pattern on the mask onto the photosensitive substrate positioned on the illuminated surface.

89. The exposure method of claim 88, further comprising:

a projection process for forming the image of the pattern on the mask using a projection optical system;

a pupil intensity distribution forming step that forms a predetermined light intensity distribution at a position conjugate to a pupil of the projection optical system or a position adjacent thereto; and

a pupil intensity distribution changing step that changes at least one of a shape or a size of the predetermined light intensity distribution.

90. The exposure method of claim 89, wherein the pupil intensity distribution changing step changes at least one of the shape and the size of the predetermined light intensity distribution in accordance with pattern characteristics of the mask;

the exposure method further comprises a polarized state changing step that changes a polarized state of the light that illuminates the illuminated surface in accordance with a change in the at least one of the shape and the size of the predetermined light intensity distribution.

91. The exposure method of claim 90, wherein the pupil intensity distribution forming step forms two areas having a high light intensity distribution spaced away from each other along a pitch direction of a line-and-space pattern formed on the mask, the exposure method further comprising a step of setting the polarized state of the light that illuminates the illuminated surface from the two areas having a high light intensity distribution to a linearly polarized state that has a polarization plane in a direction substantially orthogonal to the pitch direction.

92. The exposure method of claim 91, wherein

the two areas having a high light intensity distribution are formed symmetrically about the optical axis of the illumination optical system, and

a value σ

o defined by a ratio φ

o/φ

p satisfies the following condition;

0.7≦

σ

o

where φ

o is a diameter of a circle about the optical axis that circumscribes the two areas having a high light intensity distribution, and φ

p is a diameter of the pupil plane.

93. The exposure method of claim 91, wherein

the two areas having a high light intensity distribution are formed symmetrically about the optical axis of the illumination optical system, and

a value σ

o defined by a ratio φ

o/φ

p and σ

i defined by a ratio φ

i/φ

p satisfy the following condition;

0.5≦

σ

i/σ

o

where φ

o is a diameter of a circle about the optical axis that circumscribes the two areas having a high light intensity distribution, φ

p is a diameter of the pupil plane, and σ

i is a diameter of a circle about the optical axis that inscribes the two areas having a high light intensity distribution.

94. An exposure method for exposing a pattern on a mask positioned at a first plane onto a photosensitive substrate positioned at a second plane, comprising:

a first step that provides linearly polarized light;

a second step that illuminates the mask with the light provided in the first step;

a third step that exposes the pattern on the mask illuminated in the second step onto the photosensitive substrate; and

a fourth step that switches a polarized state of the light on the second plane between a predetermined polarized state and a nonpolarized state while controlling a loss of a light amount.

95. The exposure method of claim 94, wherein the fourth step includes a step that varies a polarization plane for the linearly polarized light.

96. The exposure method of claim 94, wherein the third step includes a step that forms an image of the pattern on the mask onto the second plane using a projection optical system, the exposure method further comprising:

a fifth step that forms a predetermined light intensity distribution at a position conjugate to a pupil of the projection optical system or a position adjacent thereto;

a sixth step that changes at least one of a shape and a size of the predetermined light intensity distribution; and

a seventh step that changes a polarized state of the light that illuminates the illuminated surface in accordance with the change in at least one of the shape and the size of the predetermined light intensity distribution.

97. An exposure method for exposing a pattern on a mask positioned at a first plane onto a photosensitive substrate positioned at a second plane, comprising:

a first step that provides light;

a second step that illuminates the mask with the light provided in the first step;

a third step that exposes the pattern on the mask illuminated in the second step onto the photosensitive substrate; and

a fourth step that corrects fluctuations of a polarized state of the light on the second plane.

98. The exposure method of claim 97, further comprising a fifth step that detects the polarized state of the light, wherein the fourth step includes a step that adjusts the polarized state on the second plane based on the polarized state of the light detected in the fifth step.

99. The exposure method of claim 97, wherein the fourth step corrects the fluctuation of the polarized state of the light on the second plane that originates in a light transmissive member in a light path of the provided light.

100. The exposure method of claim 97, wherein a time-lapse fluctuation of the polarized state on the second surface is corrected in the fourth step.

101. An illumination optical system that illuminates an illuminated surface with light from a light source, comprising:

a polarization illumination setting device that sets a polarized state of the light that illuminates the illuminated surface to a predetermined polarized state; and

an optical integrator positioned in a light path between the light source and the illuminated surface, wherein

the optical integrator comprises a first one-dimensional cylindrical lens array arranged with a pitch along a predetermined first direction, and a second one-dimensional cylindrical lens array arranged with a pitch along a second direction that crosses the first direction.

102. The illumination optical system of claim 101, wherein the first and second one-dimensional cylindrical lens arrays are integrally provided with a single light transmissive substrate.

103. The illumination optical system of claim 102, further comprising a plurality of cylindrical lens array plates having the first and second one-dimensional cylindrical arrays, wherein the plurality of cylindrical lens array plates are positioned spaced from each other along a direction of an optical axis of the illumination optical system.

104. The illumination optical system of claim 101, wherein at least one of the pitch along the first direction of the first one-dimensional cylindrical lens array and the pitch along the second direction of the second one-dimensional cylindrical lens array is equal to or less than 2 mm.

105. The illumination optical system of claim 101, wherein the polarization illumination setting device is positioned in the light path between the light source and the illuminated surface and switches the polarized state of the light that illuminates the illuminated surface between the predetermined polarized state and a nonpolarized state while controlling a loss of light amount.

106. The illumination optical system of claim 101, wherein the polarization illumination setting device is positioned in the light path between the light source and the illuminated surface and varies an orientation of a polarization plane of linearly polarized light when the predetermined polarized state is a linearly polarized state.

107. The illumination optical system of claim 101, wherein the optical integrator forms a predetermined light intensity distribution on or adjacent to a pupil plane of the illumination optical system, and

the polarization illumination setting device sets the polarized state of the light that illuminates the illuminated surface in accordance with at least one of a shape and a size of the predetermined light intensity distribution formed by the optical integrator.

108. The illumination optical system of claim 101, further comprising a polarized state fluctuation correcting device that is positioned in a light path between the light source and the illuminated surface and corrects a fluctuation of the polarized state on the illuminated surface.

109. The illumination optical system of claim 108, wherein the polarized state fluctuation correcting device corrects the fluctuation of the polarized state of the light on the illuminated surface.

110. An exposure apparatus that comprises the illumination optical system of claim 101 and that exposes a pattern on a mask onto a photosensitive substrate positioned on the illuminated surface.

111. An exposure method, comprising:

an illumination step that illuminates a mask using the illumination optical system of claim 101;

and

an exposure step that exposes a pattern on the mask onto a photosensitive substrate positioned on the illuminated surface.