Illumination optical apparatus, exposure apparatus, and device manufacturing method

• US 20070258077A1
• Filed: 04/10/2007
• Published: 11/08/2007
• Est. Priority Date: 04/17/2006
• Status: Active Grant

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: Tanaka, Hirohisa, Komatsuda, Hideki
• Granted Patent: US 9,195,069 B2
• Time in Patent Office: Days
• US Class Current: 355/71
• CPC Class Codes: G02B 27/0905 Dividing and/or superposing multiple light beams
• CPC Class Codes: G02B 27/0961 Lens arrays lens arrays per se G02B3/0006
• CPC Class Codes: G02B 27/0972 Prisms prisms per se G02B5/04
• 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 7/70208 Multiple illumination paths, e.g. radiation distribution devices, microlens illumination systems, multiplexers or demultiplexers for single or multiple projection systems
• CPC Class Codes: G03F 7/70275 Multiple projection paths, e.g. array of projection systems, microlens projection systems or tandem projection systems
• CPC Class Codes: G03F 7/70283 Mask effects on the imaging process

Abstract

An illumination optical apparatus has a beam splitting member which splits an incident beam into a first light beam and a second light beam to form a first illumination region and a second illumination region, a first light-guide optical system which guides the first light beam to the first illumination region, and a second light-guide optical system which guides the second light beam to the second illumination region locate apart from the first illumination region.

Claims

1. An illumination optical apparatus comprising:

a beam splitting member located at a position of an illumination pupil or at a position near the illumination pupil, and arranged for splitting an incident beam into a first light beam and a second light beam to form a first illumination region and a second illumination region;

a first light-guide optical system which is arranged in an optical path of the first light beam and which guides the first light beam to the first illumination region; and

a second light-guide optical system which is arranged in an optical path of the second light beam and which guides the second light beam to the second illumination region located apart from the first illumination region.

2. An illumination optical apparatus according to claim 1, comprising a polarization varying member which is arrangeable in an optical path of the illumination optical apparatus and which varies a polarization state of at least one of the first light beam and the second light beam.

3. An illumination optical apparatus according to claim 2, wherein the polarization varying member is located near the beam splitting member.

4. An illumination optical apparatus according to claim 1, wherein the first light-guide optical system and the second light-guide optical system include a common optical system which is arranged in an exiting light path of the beam splitting member and which guides the first light beam and the second light beam immediately after passage through the beam splitting member.

5. An illumination optical apparatus according to claim 4, wherein the first light-guide optical system includes a relay optical system which is arranged in an optical path of the first light beam and which guides the first light beam separated through the common optical system, to the first illumination region.

6. An illumination optical apparatus according to claim 2, comprising an optical integrator of a wavefront splitting type,

wherein the beam splitting member is located near an exit surface of the optical integrator.

7. An illumination optical apparatus according to claim 6, wherein the beam splitting member includes a plurality of folding members located so as to correspond to respective wavefront splitting regions of the optical integrator.

8. An illumination optical apparatus according to claim 6, wherein the polarization varying member includes a plurality of optical rotation members located so as to correspond to respective wavefront splitting regions of the optical integrator.

9. An illumination optical apparatus according to claim 2, comprising an optical integrator, and an imaging optical system located behind the optical integrator,

wherein the beam splitting member is located at a position of a pupil of the imaging optical system or at a position near the pupil.

10. An illumination optical apparatus according to claim 9, wherein the beam splitting member includes a folding member which folds a portion of the incident beam to convert it into the first light beam traveling along a first direction, and a light transmitting portion for transmitting a portion of the incident beam without folding it.

11. An illumination optical apparatus according to claim 10, wherein the polarization varying member includes an optical rotation member provided corresponding to the folding member.

12. An illumination optical apparatus according to claim 9, wherein the beam splitting member includes a first folding member which folds a portion of the incident beam to convert it into the first light beam traveling along a first direction, and a second folding member which folds a portion of the incident beam to convert it into the second light beam traveling along a second direction.

13. An illumination optical apparatus according to claim 12, wherein the polarization varying member includes an optical rotation member provided corresponding to at least one of the first folding member and the second folding member.

14. An illumination optical apparatus according to claim 1, comprising a common optical system which guides light from a light source to the beam splitting member.

15. An illumination optical apparatus according to claim 14, wherein the common optical system includes a variator which includes an ability to vary a first illumination condition in the first illumination region and a second illumination condition in the second illumination region.

26. An exposure apparatus comprising the illumination optical apparatus as set forth in claim 1, the exposure apparatus being arranged to effect exposure of predetermined patterns illuminated by the illumination optical apparatus, on a photosensitive substrate.

27. An exposure apparatus according to claim 26, comprising a projection optical system for projecting a pattern image of a first mask illuminated by the first illumination region and a pattern image of a second mask illuminated by the second illumination region, onto the photosensitive substrate.

28. A device manufacturing method comprising:

exposing the predetermined patterns on the photosensitive substrate using the exposure apparatus as set forth in claim 26;

and

developing the photosensitive substrate after the exposure step.

16. An illumination optical apparatus comprising:

a beam splitting member which is arranged in an optical path of an incident beam and which splits the incident beam into a first light beam and a second light beam to form a first illumination region and a second illumination region;

a first light-guide optical system which is arranged in an optical path of the first light beam and which guides the first light beam to the first illumination region;

a second light-guide optical system which is arranged in an optical path of the second light beam and which guides the second light beam to the second illumination region located apart from the first illumination region; and

a common optical system which guides light from a light source to the beam splitting member;

wherein the common optical system includes a variator which includes an ability to vary a first illumination condition in the first illumination region and a second illumination condition in the second illumination region.

17. An illumination optical apparatus according to claim 16, wherein a polarization variator which sets the first light beam in a desired polarization state in the first illumination region and which sets the second light beam in a desired polarization state in the second illumination region is located in an incident side optical path of the variator or in an optical path between the variator and the beam splitting member.

29. An exposure apparatus comprising the illumination optical apparatus as set forth in claim 16, the exposure apparatus being arranged to effect exposure of predetermined patterns illuminated by the illumination optical apparatus, on a photosensitive substrate.

30. An exposure apparatus according to claim 29, comprising a projection optical system for projecting a pattern image of a first mask illuminated by the first illumination region and a pattern image of a second mask illuminated by the second illumination region, onto the photosensitive substrate.

31. A device manufacturing method comprising:

exposing the predetermined patterns on the photosensitive substrate using the exposure apparatus as set forth in claim 29;

and

developing of the photosensitive substrate after the exposure step.

18. An illumination optical apparatus comprising:

a beam splitting member which is arranged in an optical path of an incident beam and which splits the incident beam into a first light beam and a second light beam to form a first illumination region and a second illumination region;

a first light-guide optical system which is arranged in an optical path of the first light beam and which guides the first light beam to the first illumination region;

a second light-guide optical system which is arranged in an optical path of the second light beam and which guides the second light beam to the second illumination region located apart from the first illumination region; and

a setting member located in an incident side optical path of the beam splitting member and arranged for setting each of a first illumination condition in the first illumination region and a second illumination condition in the second illumination region.

19. An illumination optical apparatus according to claim 18, wherein the first light-guide optical system and the second light-guide optical system include a common optical system which is arranged in an exit optical path of the beam splitting member and which guides the first light beam and the second light beam immediately after passage through the beam splitting member.

20. An illumination optical apparatus according to claim 18, wherein the setting member includes a varying member which includes an ability to vary each of the first illumination condition in the first illumination region and the second illumination condition in the second illumination region.

21. An illumination optical apparatus according to claim 18, wherein the setting member includes a polarization setting member which sets the first illumination region in a first polarized illumination state and which sets the second illumination region in a second polarized illumination state.

22. An illumination optical apparatus according to claim 18, wherein the setting member changes a light intensity distribution on an illumination pupil to change an illumination condition in the first illumination region and to change an illumination condition in the second illumination region.

23. An illumination optical apparatus according to claim 22, wherein the setting member includes a diffractive optical element which diffracts incident light to form a desired light intensity distribution on the illumination pupil, and a power-varying optical system which varies the light intensity distribution on the illumination pupil.

24. An illumination optical apparatus according to claim 18, wherein the setting member includes a polarizing member located on the light source side and in proximity of the beam splitting member.

25. An illumination optical apparatus according to claim 18, wherein the beam splitting member is located at or near an illumination pupil.

32. An exposure apparatus comprising the illumination optical apparatus as set forth in claim 18, the exposure apparatus being arranged to effect exposure of predetermined patterns illuminated by the illumination optical apparatus, on a photosensitive substrate.

33. An exposure apparatus according to claim 32, comprising a projection optical system for projecting a pattern image of a first mask illuminated by the first illumination region and a pattern image of a second mask illuminated by the second illumination region, onto the photosensitive substrate.

34. A device manufacturing method comprising:

exposing the predetermined patterns on the photosensitive substrate using the exposure apparatus as set forth in claim 32;

and

developing of the photosensitive substrate after the exposure step.