Illumination optical assembly, exposure device, and device manufacturing method

• US 9,523,918 B2
• Filed: 11/25/2011
• Issued: 12/20/2016
• Est. Priority Date: 06/13/2011
• Status: Active Grant

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: Miyake, Norio, Kato, Kinya
• Primary Examiner(s): Persaud, Deoram
• Application Number:
  US14/126,126
• Publication Number:
  US 20140211174A1
• Time in Patent Office: 1,852 Days
• US Class Current: 1/1
• CPC Class Codes: G02B 26/0816 by means of one or more reflecting elements
• CPC Class Codes: G02B 27/0927 Systems for changing the beam intensity distribution, e.g. Gaussian to top-hat
• CPC Class Codes: G02B 27/286 for controlling or changing the state of polarisation, e.g. transforming one polarisation state into another G02B5/3083 takes precedence; light guide coupling means utilising polarising elements G02B6/34
• CPC Class Codes: G02B 5/3083 Birefringent or phase retarding elements G02B5/3008, G02B5/3016 take precedence; systems for polarisation control G02B27/286; manufacturing phase modulating patterns by lithographic processes G03F7/001
• CPC Class Codes: G03F 7/20 Exposure; Apparatus therefor photographic printing apparatus for making copies G03B27/00
• CPC Class Codes: G03F 7/70075 Homogenization of illumination intensity in the mask plane by using an integrator, e.g. fly's eye lens, facet mirror or glass rod, by using a diffusing optical element or by beam deflection
• 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 7/7015 Details of optical elements
• CPC Class Codes: G03F 7/70566 Polarisation control

Abstract

There is provided an illumination optical system for illuminating an illumination objective surface. The illumination optical system includes a first spatial light modulator which has a plurality of optical elements arranged on a first plane, a polarizing member which is arranged in an optical path on an illumination objective surface side with respect to the first plane and which gives a polarization state change to a first light beam passes through a first area in a plane intersecting an optical axis of the illumination optical system, the polarization state change being different from a polarization state change given to a second light beam passes through a second area in the intersecting plane, and a second spatial light modulator which has a plurality of optical elements controlled individually and arranged on a second plane, and which variably forms a light intensity distribution on an illumination pupil of the illumination optical system.

Claims

1. An illumination optical system for illuminating an illumination objective surface with light from a light source, the illumination optical system comprising:

a first spatial light modulator which has a plurality of first optical elements arranged on a first plane into which the light from the light source enters, the plurality of first optical elements being controlled individually;

an upstream optical system which condenses a light exiting from the first spatial light modulator;

a polarizing member which is arranged on a second plane into which a light exiting from the upstream optical system enters;

a second spatial light modulator which has a plurality of second optical elements arranged on a third plane into which a light exiting from the polarizing member enters, the plurality of second optical elements being controlled individually; and

a downstream optical system which distributes a light exiting from the second spatial light modulator on an illumination pupil of the illumination optical system,

wherein the polarizing member differentiates a polarization state of a first light beam passing through a first area in the second plane from a polarization state of a second light beam passing through a second area in the second plane, the second area being different from the first area, the first light beam and the second light beam being included in the light exiting from the upstream optical system.

2. The illumination optical system according to claim 1, wherein the downstream optical system images a far field pattern formed in a far field of the second spatial light modulator on the illumination pupil or at a position conjugate with the illumination pupil, the far field pattern being formed by the plurality of second optical elements of the second spatial light modulator.

3. The illumination optical system according to claim 2, wherein the downstream optical system converts a distribution in an angle direction of outgoing light beams exiting from the second spatial light modulator, into a position distribution on a cross section of outgoing light beams exiting from the downstream optical system.

4. The illumination optical system according to claim 1, wherein the third plane, on which the plurality of second optical elements of the second spatial light modulator are arranged, is placed at a position which is optically conjugate with the first plane or at a position which is in an optical Fourier transform relation with the first plane.

5. The illumination optical system according to claim 1, wherein the second plane is in an optical Fourier transform relation with the first plane.

6. The illumination optical system according to claim 1, wherein the polarizing member has a first wavelength plate which is arranged on the second plane and which changes the first light beam into light in a first polarization state, and a second wavelength plate which is arranged on the second plane and which changes the second light beam into light in a second polarization state.

7. The illumination optical system according to claim 6, wherein the polarizing member further includes a depolarizer which is arranged on the second plane and which depolarizes light incident thereto and emits the depolarized light.

8. The illumination optical system according to claim 1, wherein the polarizing member has a wavelength plate having a thickness that continuously changes in a predetermined direction.

9. The illumination optical system according to claim 1, wherein the polarizing member has a first optical rotation element which is arranged on the second plane and which changes the first light beam into light in a first polarization state, and a second optical rotation element which is arranged on the second plane and which changes the second light beam into light in a second polarization state.

10. The illumination optical system according to claim 1, wherein the polarizing member has an optical rotation member which is formed of an optical material having an optical rotation property and which has a thickness that continuously changes in a predetermined direction.

11. The illumination optical system according to claim 1, wherein the polarizing member is constructed to be exchangeable.

12. The illumination optical system according to claim 1, further comprising an optical integrator,

wherein the polarizing member is arranged in an optical path between the first spatial light modulator and the optical integrator.

13. The illumination optical system according to claim 1, wherein the second spatial light modulator has a plurality of mirror elements which are arranged two-dimensionally in the second plane, and a driving unit which individually controls and drives attitudes of the plurality of mirror elements.

14. The illumination optical system according to claim 13, wherein the driving unit changes directions of the plurality of mirror elements continuously or discretely.

15. The illumination optical system according to claim 13, wherein in a case that a group of the mirror elements of the plurality of mirror elements positioned in a first area on the second plane are designated as a first mirror element group, and that a different group of the mirror elements of the plurality of mirror elements positioned in a second area on the second plane different from the first area are designated as a second mirror element group, the driving unit controls and drives the first mirror element group so that the light, which passes through the first mirror element group, is guided to a first pupil area on an optical Fourier transformation plane of the second plane, and the driving unit controls and drives the second mirror element group so that the light, which passes through the second mirror element group, is guided to a second pupil area on the optical Fourier transformation plane of the second plane.

16. The illumination optical system according to claim 1, wherein the illumination optical system is used in combination with a projection optical system which forms a plane optically conjugate with the illumination objective surface, and the illumination pupil is positioned at a position which is optically conjugate with an aperture diaphragm of the projection optical system.

17. An exposure apparatus comprising the illumination optical system as defined in claim 1 for illuminating a predetermined pattern, wherein a photosensitive substrate is exposed with the predetermined pattern.

18. The exposure apparatus according to claim 17, further comprising a projection optical system which forms an image of the predetermined pattern on the photosensitive substrate, wherein the illumination pupil is positioned at a position optically conjugate with an aperture diaphragm of the projection optical system.

19. A method for producing a device, comprising:

exposing a photosensitive substrate with the predetermined pattern by using the exposure apparatus as defined in claim 17;

developing the photosensitive substrate to which the predetermined pattern is transferred so that a mask layer, which has a shape corresponding to the predetermined pattern, is formed on a surface of the photosensitive substrate; and

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

20. The illumination optical system according to claim 1, further comprising an intermediate optical system arranged between the polarizing member and the third plane.

21. The illumination optical system according to claim 20, wherein the second plane is arranged at a pupil of a combination optical system of the upstream optical system and the intermediate optical system.

22. The illumination optical system according to claim 20, wherein the upstream optical system and the intermediate optical system allow the first plane and the third plane to be optically conjugate with each other.

23. An illumination optical system for illuminating an illumination objective surface with light from a light source, the illumination optical system comprising:

a first spatial light modulator which has a plurality of first optical elements arranged on a first plane into which the light from the light source enters, the plurality of first optical elements being controlled individually;

a first optical system which condenses a light exiting from the first spatial light modulator;

a second spatial light modulator which has a plurality of second optical elements arranged on a second plane into which a light from the first optical system enters, the plurality of second optical elements being controlled individually;

a second optical system which condenses a light exiting from the second spatial light modulator; and

a polarizing member which is arranged on a third plane into which a light exiting from the second optical system enters;

wherein the polarizing member differentiates a polarization state of a first light beam passing through a first area in the third plane from a polarization state of a second light beam passing through a second area in the third plane, the second area being different from the first area, the first light beam and the second light beam being included in the light exiting from the second optical system.

24. The illumination optical system according to claim 23, further comprising a third optical system which distributes the first and second light beams exiting from the polarizing member on an illumination pupil of the illumination optical system.

25. The illumination optical system according to claim 23, wherein the second optical system makes the second plane and the third plane into an optical Fourier transform relation.

26. The illumination optical system according to claim 23, wherein the first optical system makes the first plane and the second plane into an optical Fourier transform relation.