Illumination optical apparatus having distribution changing member to change light amount and polarization member to set polarization in circumference direction

• US 9,678,437 B2
• Filed: 05/08/2013
• Issued: 06/13/2017
• Est. Priority Date: 04/09/2003
• Status: Expired due to Fees

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: Kudo, Takehito, Hirukawa, Shigeru
• Primary Examiner(s): LIU, CHIA HOW MICHAEL
• Application Number:
  US13/890,142
• Publication Number:
  US 20130308113A1
• Time in Patent Office: 1,497 Days
• Field of Search: 355 71, 355 67
• 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 7/701 Off-axis setting using an aperture
• 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 7/70191 Optical correction elements, filters or phase plates for controlling intensity, wavelength, polarisation, phase or the like
• 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, a polarization member arranged in an optical path of the illumination light on an incidence side of the optical integrator, which changes a polarization state of the illumination light, and a distribution changing member arranged in the optical path between the polarization member and the optical integrator, which can change a light amount distribution of the illumination light on a pupil plane of the illumination optical apparatus. The polarization member changes the polarization state of the illumination light so that a polarization direction of the illumination light, which is distributed away from an optical axis of the illumination optical apparatus on the pupil plane, is substantially coincident with a circumferential direction about the optical axis on the pupil plane.

Claims

1. An illumination optical apparatus which illuminates a pattern on a mask with illumination light, the illumination optical apparatus comprising:

an optical integrator arranged in an optical path of the illumination light;

a polarization member arranged in the optical path of the illumination light on an incidence side of the optical integrator, which changes a polarization state of the illumination light; and

a movable member arranged in the optical path between the polarization member and the optical integrator so as to change a light amount distribution of the illumination light on a pupil plane of the illumination optical apparatus,

wherein the polarization member changes the polarization state of the illumination light distributed away from an optical axis of the illumination optical apparatus on the pupil plane so that a polarization direction of the illumination light at a distribution area on the pupil plane is substantially perpendicular to a radial direction extending from the optical axis to the distribution area.

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

the distribution area on the pupil plane includes at least one area located on a predetermined circumference substantially centered around the optical axis on the pupil plane, the illumination light from the polarization member passing through the distribution area.

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

the at least one area includes a first area on a first straight line intersecting with the optical axis on the pupil plane, and

the polarization member changes the polarization state of the illumination light which is distributed to the first area.

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

the first area includes a pair of areas which are located at positions mutually symmetric with respect to the optical axis.

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

the at least one area includes a second area on a second straight line intersecting with the optical axis and the first straight line on the pupil plane, and

the polarization member changes the polarization state of the illumination light which is distributed to the second area.

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

the second area includes a pair of areas which are located at positions mutually symmetric with respect to the optical axis.

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

the first straight line and the second straight line are substantially perpendicular to each other.

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

the movable member is capable of changing the distribution area around the optical axis on the pupil plane.

9. The illumination optical apparatus according to claim 8, wherein

the movable member is capable of changing a position of the distribution area around the optical axis on the pupil plane.

10. The illumination optical apparatus according to claim 9, wherein

the movable member is capable of changing the position of the distribution area on the pupil plane in two directions individually, the two directions being orthogonal to each other.

11. The illumination optical apparatus according to claim 8, wherein

the movable member includes first and second inclined surfaces inclined relative to the optical axis, and

the illumination light is distributed away from the optical axis on the pupil plane via the first and second inclined surfaces.

12. The illumination optical apparatus according to claim 11, wherein

the movable member includes a first prism including the first inclined surface and a second prism including the second inclined surface, an interval between the first and second prisms being changeable, the first and second inclined surfaces facing each other.

13. The illumination optical apparatus according to claim 8, wherein

the movable member includes a zoom lens.

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

the polarization member includes a ½

wave plate.

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

the polarization member includes a ¼

wave plate.

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

the optical integrator includes a fly'"'"'s eye lens, and

an exit plane of the fly'"'"'s eye lens is arranged to be substantially coincident with the pupil plane.

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

the optical integrator includes a fly'"'"'s eye lens, and

an exit plane of the fly'"'"'s eye lens is arranged to be substantially coincident with an optical Fourier transform plane with respect to a plane on which the pattern is arranged.

18. An exposure apparatus which exposes a substrate with light from a pattern on a mask, the exposure apparatus comprising:

the illumination optical apparatus as defined in claim 1 which illuminates the pattern with the light; and

a projection optical system which projects an image of the pattern illuminated with the light onto the substrate.

19. The exposure apparatus according to claim 18, further comprising a stage which holds the substrate and is movable relative to the projection optical system, wherein

the projection optical system projects the image of the pattern onto the substrate held by the stage.

20. The exposure apparatus according to claim 18, wherein

the substrate is exposed with the light through a liquid.

21. The exposure apparatus according to claim 18, wherein

the distribution area on the pupil plane includes at least one area located on a predetermined circumference substantially centered around the optical axis on the pupil plane, the illumination light from the polarization member passing through the distribution area.

22. The exposure apparatus according to claim 21, wherein

the at least one area includes a first area on a first straight line intersecting with the optical axis on the pupil plane, and

the polarization member changes the polarization state of the illumination light which is distributed to the first area.

23. The exposure apparatus according to claim 22, wherein

the at least one area includes a second area on a second straight line intersecting with the optical axis and the first straight line on the pupil plane, and

the polarization member changes the polarization state of the illumination light which is distributed to the second area.

24. The exposure apparatus according to claim 18, wherein

the movable member is capable of changing the distribution area around the optical axis on the pupil plane.

25. The exposure apparatus according to claim 24, wherein

the movable member is capable of changing a position of the distribution area around the optical axis on the pupil plane.

26. The exposure apparatus according to claim 25, wherein

the movable member is capable of changing the position of the distribution area on the pupil plane in two directions individually, the two directions being orthogonal to each other.

27. The exposure apparatus according to claim 18, wherein

the optical integrator includes a fly'"'"'s eye lens, and

an exit plane of the fly'"'"'s eye lens is arranged to be substantially coincident with the pupil plane.

28. The exposure apparatus according to claim 18, wherein

the optical integrator includes a fly'"'"'s eye lens, and

an exit plane of the fly'"'"'s eye lens is arranged to be substantially coincident with an optical Fourier transform plane with respect to a plane on which the pattern is arranged.

29. A device manufacturing method, comprising:

transferring a pattern to a substrate by using the exposure apparatus as defined in claim 18; and

developing the substrate to which the pattern is transferred.

30. An exposure method for exposing a substrate with light from a pattern on a mask, the exposure method comprising:

illuminating the pattern with the light by using the illumination optical apparatus as defined in claim 1; and

projecting an image of the pattern illuminated with the light onto the substrate.

31. The exposure method according to claim 30, wherein

the substrate is exposed with the light through a liquid.

32. A device manufacturing method, comprising:

transferring a pattern to a substrate by using the exposure method as defined in claim 30; and

developing the substrate to which the pattern is transferred.