Beam transforming element, illumination optical apparatus, exposure apparatus, and exposure method with two optical elements having different thicknesses

• US 20090147234A1
• Filed: 01/27/2009
• Published: 06/11/2009
• Est. Priority Date: 11/20/2003
• Status: Abandoned Application

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: Toyoda, Mitsunori
• Application Number:
  US12/320,468
• Publication Number:
  US 20090147234A1
• Time in Patent Office: Days
• US Class Current: 355/71
• 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

A beam transforming element for forming a predetermined light intensity distribution on a predetermined surface on the basis of an incident beam includes a first basic element made of an optical material with optical activity, for forming a first region distribution of the predetermined light intensity distribution on the basis of the incident beam; and a second basic element made of an optical material with optical activity, for forming a second region distribution of the predetermined light intensity distribution on the basis of the incident beam, wherein the first basic element and the second basic element have their respective thicknesses different from each other along a direction of transmission of light.

Claims

1. An apparatus which illuminates a surface to be illuminated with radiation from a radiation source, the apparatus comprising:

a polarization state converter arranged in an illumination path;

a first crystal optical element having a first thickness along an optical axis direction; and

a second crystal optical element having a second thickness along an optical axis direction;

wherein the first and second crystal optical elements are arranged in a plane disposed in an illumination path of the apparatus.

2. The apparatus according to claim 1, wherein the plane is arranged in the illumination path between the polarization state converter and the surface to be illuminated.

3. The apparatus according to claim 2, wherein the first and second crystal optical elements are made of an optical material with optical activity.

4. The apparatus according to claim 3, wherein optic axes of the optical material of the first and second crystal optical elements are aligned along the optical axis direction of the apparatus.

5. The apparatus according to claim 4, wherein the first and second thicknesses are different.

6. The apparatus according to claim 2, further comprising:

a diffractive surface arranged in an illumination path of the apparatus which generates a first diffracted radiation and a second diffracted radiation from the radiation from the radiation source, the first and second diffracted radiations reach different regions on an illumination pupil of the apparatus.

7. The apparatus according to claim 6, wherein the diffractive surface includes a first diffractive surface arranged between the first crystal optical element and the illumination pupil, and a second diffractive surface arranged between the second crystal optical element and the illumination pupil.

8. The apparatus according to claim 2, further comprising an optical integrator arranged between the first and second crystal optical elements and the surface to be illuminated.

9. The apparatus according to claim 2, further comprising:

a diffractive surface which is arranged in an illumination path of the apparatus, and which forms a first region distribution of the predetermined light intensity distribution and a second region distribution of the predetermined light intensity distribution on the basis of radiation from the radiation source,

the first crystal optical element provides a first rotation angle to an incident linearly polarized radiation, and the linearly polarized radiation from the first crystal optical element propagates to the first region distribution;

the second crystal optical element provides a second rotation angle to an incident linearly polarized radiation, the second thickness differs from the first thickness, and the linearly polarized radiation from the second crystal optical element propagates to the second region distribution.

10. The apparatus according to claim 9, further comprising an optical integrator arranged between the first and second crystal optical elements and the surface to be illuminated.

11. The apparatus according to claim 10, wherein the diffractive surface is arranged between the first and second crystal optical elements and the surface to be illuminated.

12. The apparatus according to claim 9, wherein the diffractive surface is arranged between the first and second crystal optical elements and the surface to be illuminated.

13. The apparatus according to claim 2, wherein the first crystal optical element and the second crystal optical element are integrally formed.

14. The apparatus according to claim 2, further comprising a polarization monitor arranged downstream of the first and second crystal optical elements.

15. The apparatus according to claim 1, wherein a polarization state of the beam from the first and second crystal optical elements is based on an influence of an optical member disposed in an illumination path between the light source and the surface to be illuminated.

16. The apparatus according to claim 15, wherein the optical member includes a reflective member.

17. An exposure apparatus comprising the apparatus as defined in claim 1, wherein the exposure apparatus illuminates a predetermined pattern, and projects an image of the predetermined pattern onto a photosensitive substrate on the surface to be illuminated.

18. The exposure apparatus according to claim 17, wherein an illumination pupil distribution on or near an illumination pupil of the apparatus is a distribution in at least a part of a predetermined annular region centered around an optical axis of the apparatus.

19. The exposure apparatus according to claim 17, wherein a polarization state of the beam from the first and second crystal optical elements is set based on an influence of an optical member disposed in an illumination path between the light source and the photosensitive substrate on the surface to be illuminated.

20. The exposure apparatus according to claim 19, wherein the optical member includes a reflective member.

21. The exposure apparatus according to claim 17, wherein a polarization state of the beam at an illumination pupil is set so that light illuminating the photosensitive substrate is in a polarization state in which a principal component is s-polarized light.

22. An exposure method comprising:

illuminating a predetermined pattern using the exposure apparatus as defined in claim 17, and

projecting an image of the predetermined pattern onto a photosensitive substrate.

23. A device manufacturing method comprising:

illuminating a predetermined pattern using the exposure apparatus as defined in claim 17;

projecting an image of the predetermined pattern onto a photosensitive substrate; and

developing the photosensitive substrate.

24. An exposure method comprising:

supplying radiation;

passing the supplied radiation through a polarization state converter,

passing the radiation from the polarization state converter through a first crystal optical element having a first thickness along a traveling direction of an incident radiation,

passing the radiation from the polarization state converter through a second crystal optical element having a second thickness along the traveling direction of an incident radiation, the first and second thicknesses being different from each other, the first and second crystal optical elements arranged in a plane crossing the traveling direction; and

projecting an image of a pattern illuminated with the radiation passed through the first and second crystal optical elements, onto a photosensitive substrate.

25. The method according to claim 24, wherein the first and second crystal optical elements are made of an optical material with optical activity.

26. The method according to claim 25, wherein optic axes of the optical material of the first and second crystal optical elements are aligned along the traveling direction of the radiation.

27. The method according to claim 26, further comprising:

generating a first diffracted radiation and a second diffracted radiation, the first and second diffracted radiations reach different regions on an illumination pupil;

optically rotating the first diffracted radiation with the first crystal optical element; and

optically rotating the second diffracted radiation with the second crystal optical element, wherein

the first and second crystal optical elements have thicknesses different from each other along a direction of transmission of the radiation.

28. The method according to claim 27, further comprising projecting the radiations from the first and second crystal optical elements through an optical integrator.

29. The method according to claim 28, wherein the first and second diffracted radiations are generated by radiations from the first and second crystal optical elements.

30. The method according to claim 24, wherein the first crystal optical element and the second crystal optical element are integrally formed.

31. The method according to claim 24, wherein polarization states of beams from the first and second crystal optical elements are set based on an influence of an optical member in an illumination path between a light source of the radiation and a substrate arranged on the surface to be illuminated.

32. The method according to claim 31, wherein the optical member is reflective.

33. A device manufacturing method comprising:

projecting an image of a pattern onto a photosensitive substrate using the exposure method according to claim 24; and

developing the photosensitive substrate.