Illumination optical apparatus, exposure apparatus, and exposure method with optical member with optical rotatory power having different thicknesses to rotate linear polarization direction

• US 9,164,209 B2
• Filed: 07/14/2011
• Issued: 10/20/2015
• Est. Priority Date: 11/20/2003
• Status: Active Grant

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: Toyoda, Mitsunori
• Primary Examiner(s): LIU, CHIA HOW MICHAEL
• Application Number:
  US13/137,003
• Publication Number:
  US 20110273693A1
• Time in Patent Office: 1,559 Days
• Field of Search: 355/71, 355/67, 355/53, 359/494
• US Class Current: 1/1
• CPC Class Codes: G02B 27/0927 Systems for changing the beam intensity distribution, e.g. Gaussian to top-hat
• CPC Class Codes: G02B 27/0944 Diffractive optical elements, e.g. gratings, holograms gratings per se G02B5/18; holograms used as optical elements per se G02B5/32
• CPC Class Codes: G02B 27/28 for polarising used in stereoscopes G02B30/25
• CPC Class Codes: G02B 27/4233 having a diffractive element [DOE] contributing to a non-imaging application diffusers having a diffractive element G02B5/0252; filters having a diffractive element G02B5/203; systems for controlling the direction of light having diffractive elements G02B26/0808; scanning systems having diffractive elements G02B26/106; beam shaping systems using diffractive optical elements G02B27/0944; beam splitting or combining systems operating by diffraction G02B27/1086
• CPC Class Codes: G02B 27/4261 having a diffractive element with major polarization dependent properties
• CPC Class Codes: G02B 5/3025 Polarisers, i.e. arrangements capable of producing a definite output polarisation state from an unpolarised input state G02B5/3008, G02B5/3016 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 7/70108 Off-axis setting using a light-guiding element, e.g. diffractive optical elements [DOEs] or light guides
• CPC Class Codes: G03F 7/70158 Diffractive optical elements
• CPC Class Codes: G03F 7/70566 Polarisation control

Abstract

An illumination optical apparatus illuminates a pattern on a mask with illumination light. The illumination optical apparatus includes an optical integrator arranged in an optical path of the illumination light, and a polarization member made of optical material with optical rotatory power, which is arranged in the optical path on an incidence side of the optical integrator, and which changes a polarization state of the illumination light. The illumination light from the polarization member is irradiated onto the pattern through a pupil plane of the illumination optical apparatus.

Claims

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

an optical member made of an optical material with optical rotatory power, which rotates a polarization direction of a linear polarization incident on the optical member, the optical member being arranged in an optical path of the beam so that an optic axis of the optical material of the optical member is substantially parallel to an optical axis of the illumination optical apparatus at a location where the optical material is arranged;

an optical integrator arranged in the optical path of the beam on an exit side of the optical member; and

an optical system arranged in the optical path between the optical member and the optical integrator, which locates the optical member and an entrance surface of the optical integrator substantially in the relation of Fourier transform so as to form an illumination area on a pupil plane of the illumination optical apparatus, the pupil plane substantially being located at a rear focal plane of the optical integrator, wherein

the optical member includes a first portion having a first length and a second portion having a second length different from the first length,

the first and second lengths are a length between an entrance surface and an exit surface of the optical material of the optical member in a direction of the optical axis,

the illumination area on the pupil plane is formed so that a first beam passing through the first portion of the optical member passes through a first region of the illumination area and a second beam passing through the second portion of the optical member passes through a second region of the illumination area, the second region being different from the first region, the first and second beams being part of the beam, and

the beam of which a polarization direction is rotated by the optical member on the basis of the optical rotatory power is irradiated onto the object through the pupil plane.

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

the optical member includes a first basic element and a second basic element, the first basic element including the first portion, the second basic element including the second portion.

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

a predetermined surface of the first and second basic elements are arranged in a plane substantially perpendicular to the optical axis.

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

the first basic element and the second basic element are integrally formed.

5. The illumination optical apparatus according to claim 1, further comprising:

a first optical unit including a first folding mirror;

a second optical unit arranged in the optical path of the beam from the first folding mirror; and

a third optical unit including a second folding mirror and being arranged in the optical path of the beam from the second folding minor, wherein

the second optical unit includes the optical member, the optical system and the optical integrator.

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

the optical member includes a first basic element and a second basic element, the first basic element including the first portion, the second basic element including the second portion.

7. The illumination optical apparatus according to claim 6, wherein

the first basic element and the second basic element are integrally formed.

8. An exposure apparatus which exposes a substrate with a beam from a predetermined pattern on a mask, the exposure apparatus comprising

the illumination optical apparatus as defined in claim 1, which illuminates the predetermined pattern;

and

a projection optical system which projects an image of the predetermined pattern, being illuminated by the illumination optical apparatus, onto the substrate.

9. A device manufacturing method comprising:

illuminating the predetermined pattern using the exposure apparatus as defined in claim 8;

projecting the image of the predetermined pattern onto the photosensitive substrate by using the exposure apparatus as defined in claim 8; and

developing the photosensitive substrate.

10. The illumination optical apparatus according to claim 1, wherein the beam, of which the polarization direction is rotated by the optical member, is irradiated onto the object in a polarization state in which a principal component is S-polarized light.

11. The illumination optical apparatus according to claim 1, wherein the optical member rotates a polarization direction of the beam so that the polarization direction of the beam in a region on the pupil plane is substantially coincident with a circumferential direction about the optical axis, the region being distributed away from the optical axis on the pupil plane.

12. The illumination optical apparatus according to claim 11, wherein the region on the pupil plane is an annular region about the optical axis.

13. The illumination optical apparatus according to claim 11, wherein the region on the pupil plane comprises a plurality of substantially discrete regions within an annular region about the optical axis.

14. The illumination optical apparatus according to claim 11, wherein the region on the pupil plane comprises a plurality of substantially discrete regions which are aligned along a circumference about the optical axis.

15. The illumination optical apparatus according to claim 14, wherein the plurality of the regions on the pupil plane comprises a pair of regions arranged symmetrically with respect to the optical axis.

16. The illumination optical apparatus according to claim 11, wherein the optical integrator comprises a fly'"'"'s eye lens.

17. The illumination optical apparatus according to claim 11, wherein the optical integrator is an optical integrator of wavefront splitting type.

18. The illumination optical apparatus according to claim 11, wherein the optical system comprises a lens system of which a rear focal plane is substantially arranged at an entrance surface of the optical integrator, and

wherein the optical member is arranged so that the optical member and a front focal plane of the lens system are substantially conjugate with each other.

19. The illumination optical apparatus according to claim 11, wherein the optical system comprises a first lens system and a second lens system, the first lens system being arranged between the optical member and the optical integrator so as to form an intermediate conjugated position substantially conjugate with the optical member, the second lens system being arranged between the intermediate conjugated position and the optical integrator so that the intermediate conjugated position and an entrance surface of the optical integrator are substantially in the relation of Fourier transform.

20. The exposure apparatus according to claim 8, wherein the beam from the pupil plane of the illumination optical apparatus is irradiated onto the mask in a polarization state in which a principal component is S-polarized light.

21. The exposure apparatus according to claim 8, wherein the optical member of the illumination optical apparatus rotates a polarization direction of the beam so that the polarization direction of the beam in a region on the pupil plane is substantially coincident with a circumferential direction about the optical axis, the region being distributed away from the optical axis on the pupil plane.

22. The exposure apparatus according to claim 21, wherein the region on the pupil plane is an annular region about the optical axis.

23. The exposure apparatus according to claim 21, wherein the region on the pupil plane comprises a plurality of substantially discrete regions within an annular region about the optical axis.

24. The exposure apparatus according to claim 21, wherein the region on the pupil plane comprises a plurality of substantially discrete regions which are aligned along a circumference about the optical axis.

25. The exposure apparatus according to claim 24, wherein the plurality of the regions on the pupil plane comprises a pair of regions arranged symmetrically with respect to the optical axis.

26. The exposure apparatus according to claim 21, wherein the optical integrator comprises a fly'"'"'s eye lens.

27. The exposure apparatus according to claim 21, wherein the optical system comprises a first lens system and a second lens system, the first lens system being arranged between the optical member and the optical integrator so as to form an intermediate conjugated position substantially conjugate with the optical member, the second lens system being arranged between the intermediate conjugated position and the optical integrator so that the intermediate conjugated position and an entrance surface of the optical integrator are substantially in the relation of Fourier transform.

28. The exposure apparatus according to claim 21, wherein the optical integrator is an optical integrator of wavefront splitting type.

29. The exposure apparatus according to claim 21, wherein the optical system comprises a lens system of which a rear focal plane is substantially arranged at an entrance surface of the optical integrator, and wherein the optical member is arranged so that the optical member and a front focal plane of

the lens system are substantially conjugate with each other.