Optical illumination device, exposure device and exposure method

• US 6,913,373 B2
• Filed: 05/27/2003
• Issued: 07/05/2005
• Est. Priority Date: 05/27/2002
• Status: Active Grant

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: Toyoda, Mitsunori, Tanaka, Hirohisa, Tanitsu, Osamu
• Primary Examiner(s): O'Shea, Sandra
• Assistant Examiner(s): Alavi, Ali
• Application Number:
  US10/445,022
• Publication Number:
  US 20040036977A1
• Time in Patent Office: 770 Days
• Field of Search: 362/268, 362/331, 362/326, 362/259, 362/335, 359/621, 359/622, 359/623, 359/624, 353/38, 355/67, 501/54
• US Class Current: 362/268
• 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 7/70158 Diffractive optical elements

Abstract

The present invention provides an optical illumination device that permits an increase in the fill of a multiplicity of light sources that constitute a secondary source formed on an illuminated pupil plane. A fly'"'"'s eye lens that forms a multiplicity of light sources from a light beam emitted by an optical integrator is disposed in the optical path between the optical integrator and an irradiation surface. The fly'"'"'s eye lens comprises, in order from the light-source side, a first fly'"'"'s eye member and a second fly'"'"'s eye member. A cylindrical lens group arranged in a first direction is formed on each of the light source-side surface of a first fly'"'"'s eye member and the light source-side surface of a second fly'"'"'s eye member, and a cylindrical lens is group arranged in a second direction orthogonal to the first direction is formed on each of the irradiation surface side surface of the first fly'"'"'s eye member and the irradiation surface side surface of the second fly'"'"'s eye member.

Claims

1. An optical illumination device for illuminating an irradiation surface with a light beam from a light source, comprising:

an optical integrator which is disposed in an optical path between the light source and the irradiation surface; and

a fly'"'"'s eye lens which is disposed in an optical path between the optical integrator and the irradiation surface and which forms a multiplicity of light sources from the light beam output from the optical integrator,

the fly'"'"'s eye lens comprising, in order from the light source side, a first fly'"'"'s eye member and a second fly'"'"'s eye member,

each of the light source-side surface of the first fly'"'"'s eye member and the light source-side surface of the second fly'"'"'s eye member being formed with a cylindrical lens group such that the cylindrical lenses are arranged in a first direction, and

each of the irradiation surface-side surface of the first fly'"'"'s eye member and the irradiation surface-side surface of the second fly'"'"'s eye member being formed with a cylindrical lens group such that the cylindrical lenses are arranged in a second direction orthogonal to the first direction.

2. The optical illumination device according to claim 1,

wherein, when the radius of curvature of each cylindrical lens formed on the light source-side surface of the first fly'"'"'s eye member is Ra, the radius of curvature of each cylindrical lens formed on the light source-side surface of the second fly'"'"'s eye member is Rb, the radius of curvature of each cylindrical lens formed on the irradiation surface-side surface of the first fly'"'"'s eye member is Rc, and the radius of curvature of each cylindrical lens formed on the irradiation surface-side surface of the second fly'"'"'s eye member is Rd, the conditions 0.3<

Rd/Rc<

0.5 and 0.3<

Rb/Ra<

0.5 are satisfied.

3. The optical illumination device according to claim 2, wherein the first fly'"'"'s eye member comprises silica and the second fly'"'"'s eye member comprises a crystal material that is transmissive with respect to light with a wavelength of 250 nm or less.

4. The optical illumination device according to claim 2, wherein any one of the first fly'"'"'s eye member and the second fly'"'"'s eye member in which region irradiated with light at an energy density equal to or more than 1 mJ/cm² is present comprises a crystal material that is transmissive with respect to light with a wavelength of 250 nm or less.

5. The optical illumination device according to claim 1, wherein the first fly'"'"'s eye member comprises silica and the second fly'"'"'s eye member comprises a crystal material that is transmissive with respect to light with a wavelength of 250 nm or less.

6. The optical illumination device according to claim 5, wherein the crystal material contains at least one material selected from a group consisting of fluorite, quartz crystal, magnesium fluoride, barium fluoride, lithium fluoride, lanthanum fluoride, strontium fluoride, beryllium fluoride, sodium fluoride, LICAF, and LISAF.

7. The optical illumination device according to claim 1, wherein any one of the first fly'"'"'s eye member and the second fly'"'"'s eye member in which region irradiated with light at an energy density equal to or more than 1 mJ/cm² is present comprises a crystal material that is transmissive with respect to light with a wavelength of 250 nm or less.

8. The optical illumination device according to claim 7, wherein the crystal material contains at least one material selected from a group consisting of fluorite, quartz crystal, magnesium fluoride, barium fluoride, lithium fluoride, lanthanum fluoride, strontium fluoride, beryllium fluoride, sodium fluoride, LICAF, and LISAF.

9. The optical illumination device according to claim 7, wherein alignment marks for aligning the first fly'"'"'s eye member and the second fly'"'"'s eye member are formed on the first fly'"'"'s eye member and the second fly'"'"'s eye member.

10. The optical illumination device according to claim 7, wherein a corrective filter for correcting the illuminance distribution on the irradiation surface is provided at least one of an entrance pupil position with respect to the first direction of the fly'"'"'s eye lens or in the vicinity of this entrance pupil position, and an entrance pupil position with respect to the second direction of the fly'"'"'s eye lens or in the vicinity of this entrance pupil position.

11. The optical illumination device according to claim 7, wherein at least one of the pitch in the first direction of the cylindrical lens groups formed on the light source-side surface of the first fly'"'"'s eye member and the light source-side surface of the second fly'"'"'s eye member, and the pitch in the second direction of the cylindrical lens groups formed on the irradiation surface-side surface of the first fly'"'"'s eye member and the irradiation surface-side surface of the second fly'"'"'s eye member is equal to or less than 2 mm.

12. The optical illumination device according to claim 7, wherein at least one of the first fly'"'"'s eye member and the second fly'"'"'s eye member is movable.

13. The optical illumination device according to claim 1, wherein alignment marks for aligning the first fly'"'"'s eye member and the second fly'"'"'s eye member are formed on the first fly'"'"'s eye member and the second fly'"'"'s eye member.

14. The optical illumination device according to claim 13, wherein the alignment marks include linear marks extending in the second direction in the light source-side surface of the first fly'"'"'s eye member and in the light source-side surface of the second fly'"'"'s eye member, and linear marks extending in the first direction in the irradiation surface-side surface of the first fly'"'"'s eye member and in the irradiation surface-side surface of the second fly'"'"'s eye member.

15. The optical illumination device according to claim 13, wherein a corrective filter for correcting the illuminance distribution on the irradiation surface is provided at least one of an entrance pupil position with respect to the first direction of the fly'"'"'s eye lens or in the vicinity of this entrance pupil position, and an entrance pupil position with respect to the second direction of the fly'"'"'s eye lens or in the vicinity of this entrance pupil position.

16. The optical illumination device according to claim 1, wherein a corrective filter for correcting the illuminance distribution on the irradiation surface is provided at least one of an entrance pupil position with respect to the first direction of the fly'"'"'s eye lens or in the vicinity of this entrance pupil position, and an entrance pupil position with respect to the second direction of the fly'"'"'s eye lens or in the vicinity of this entrance pupil position.

17. The optical illumination device according to claim 16, wherein second alignment marks for aligning the corrective filter with the first fly'"'"'s eye member or the second fly'"'"'s eye member are formed on the corrective filter.

18. The optical illumination device according to claim 17, wherein the second alignment marks include linear marks formed in the first direction or the second direction.

19. The optical illumination device according to the claim 1, wherein at least one of the pitch in the first direction of the cylindrical lens groups formed on the light source-side surface of the first fly'"'"'s eye member and the light source-side surface of the second fly'"'"'s eye member, and the pitch in the second direction of the cylindrical lens groups formed on the irradiation surface-side surface of the first fly'"'"'s eye member and the irradiation surface-side surface of the second fly'"'"'s eye member is equal to or less than 2 mm.

20. The optical illumination device according to claim 19, wherein at least one of the first fly'"'"'s eye member and the second fly'"'"'s eye member is movable.

21. The optical illumination device according to claim 1, wherein at least one of the first fly'"'"'s eye member and the second fly'"'"'s eye member is movable.

22. The optical illumination device according to claim 21, wherein at least one of the first fly'"'"'s eye member and the second fly'"'"'s eye member is movable along the optical axis for the purpose of controlling the size of the illumination region on the irradiation surface or controlling the illuminance distribution on the irradiation surface.

23. The optical illumination device according to claim 22, wherein at least one of the first fly'"'"'s eye member and the second fly'"'"'s eye member is movable in at least one of the first direction and the second direction for the purpose of controlling the size of the illumination region on the irradiation surface or controlling the illuminance distribution on the irradiation surface.

24. The optical illumination device according to claim 23, wherein at least one of the first fly'"'"'s eye member and the second fly'"'"'s eye member is rotatable around at least one of the first direction and the second direction for the purpose of controlling the illuminance distribution on the illumination pupil plane.

25. The optical illumination device according to claim 22, wherein at least one of the first fly'"'"'s eye member and the second fly'"'"'s eye member is rotatable around at least one of the first direction and the second direction for the purpose of controlling the illuminance distribution on the illumination pupil plane.

26. The optical illumination device according to claim 21, wherein at least one of the first fly'"'"'s eye member and the second fly'"'"'s eye member is movable in at least one of the first direction and the second direction for the purpose of controlling the size of the illumination region on the irradiation surface or controlling the illuminance distribution on the irradiation surface.

27. The optical illumination device according to claim 26, wherein at least one of the first fly'"'"'s eye member and the second fly'"'"'s eye member is rotatable around at least one of the first direction and the second direction for the purpose of controlling the illuminance distribution on the illumination pupil plane.

28. The optical illumination device according to claim 21, wherein at least one of the first fly'"'"'s eye member and the second fly'"'"'s eye member is rotatable aroun at least one of the first direction and the second direction for the purpose of controlling the illuminance distribution on the illumination pupil plane.

29. An exposure device, comprising:

the optical illumination device according to claim 1; and

an optical projection system for projection-exposing a pattern of a mask disposed on the irradiation surface onto a photosensitive substrate.

30. The exposure device according to claim 29, wherein the mask pattern is projection-exposed onto the photosensitive substrate by causing the mask and the photosensitive substrate to undergo relative motion with respect to the optical projection system in a direction that corresponds optically with the first direction.

31. An exposure method, comprising the steps of:

illuminating a mask via the optical illumination device according to claim 1; and

projection-exposing the image of the pattern on the mask thus illuminated onto a photosensitive substrate.

32. The exposure method according to claim 31, wherein the mask pattern is projection-exposed onto the photosensitive substrate by causing the mask and the photosensitive substrate to undergo relative motion with respect to the optical projection system in a direction that corresponds optically with the first direction.

33. An optical illumination device for illuminating an irradiation surface with a light beam from a light source, comprising:

an optical integrator which is disposed in an optical path between the light source and the irradiation surface; and

a fly'"'"'s eye lens which is disposed in an optical path between the optical integrator and the irradiation surface and which forms a multiplicity of light sources from the light beam output from the optical integrator,

the fly'"'"'s eye lens comprising, in order from the light source side, a first fly'"'"'s eye member and a second fly'"'"'s eye member,

each of the light source-side surface of the first fly'"'"'s eye member and the light source-side surface of the second fly'"'"'s eye member being formed with a cylindrical lens group such that the cylindrical lenses are arranged in a first direction, and

each of the irradiation surface-side surface of the first fly'"'"'s eye member and the irradiation surface-side surface of the second fly'"'"'s eye member being formed with a cylindrical lens group such that the cylindrical lenses are arranged in a second direction orthogonal to the first direction,

wherein at least one of the pitch in the first direction of the cylindrical lens groups formed on the light source-side surface of the first fly'"'"'s eye member and the light source-side surface of the second fly'"'"'s eye member, and the pitch in the second direction of the cylindrical lens groups formed on the irradiation surface-side surface of the first fly'"'"'s eye member and the irradiation surface-side surface of the second fly'"'"'s eye member is equal to or less than 2 mm.

34. An optical illumination device for illuminating an irradiation surface with a light beam from a light source, comprising:

an optical integrator which is disposed in an optical path between the light source and the irradiation surface; and

a fly'"'"'s eye lens which is disposed in an optical path between the optical integrator and the irradiation surface and which forms a multiplicity of light sources from the light beam output from the optical integrator,

the fly'"'"'s eye lens comprising, in order from the light source side, a first fly'"'"'s eye member and a second fly'"'"'s eye member,

each of the light source-side surface of the first fly'"'"'s eye member and the light source-side surface of the second fly'"'"'s eye member being formed with a cylindrical lens group such that the cylindrical lenses are arranged in a first direction, and

each of the irradiation surface-side surface of the first fly'"'"'s eye member and the irradiation surface-side surface of the second fly'"'"'s eye member being formed with a cylindrical lens group such that the cylindrical lenses are arranged in a second direction orthogonal to the first direction,

wherein at least one of the first fly'"'"'s eye member and the second fly'"'"'s eye member is movable.