Exposure method and apparatus, and method for fabricating device with light amount distribution having light larger and different linear polarization states in an on-axis area and a plurality of off-axis areas

• US 9,146,474 B2
• Filed: 03/12/2009
• Issued: 09/29/2015
• Est. Priority Date: 04/09/2003
• Status: Active Grant

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: Kudo, Takehito, Hirukawa, Shigeru
• Primary Examiner(s): LIU, CHIA HOW MICHAEL
• Application Number:
  US12/382,277
• Publication Number:
  US 20090185156A1
• Time in Patent Office: 2,392 Days
• Field of Search: 355/71, 355/67, 355/53
• US Class Current: 1/1
• 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 exposure method and apparatus that illuminates a pattern with an illumination system to expose a substrate through a projection system are provided. The pattern is illuminated with illumination light having a light amount distribution, which is set such that an amount of light is larger in an on-axis area substantially including an optical axis and in a plurality of off-axis areas arranged out of the optical axis than in an area other than the on-axis area and the plurality of off-axis areas on a pupil plane of the illumination system. The polarization states of the illumination light are different between the on-axis area and the off-axis areas.

Claims

1. An exposure method for illuminating a pattern with an illumination system to expose a substrate through a projection system, comprising:

illuminating the pattern with illumination light having a light amount distribution, which is set such that an amount of light on a pupil plane of the illumination system is larger in an on-axis area substantially including an optical axis and in a plurality of off-axis areas arranged away from the optical axis than in an area other than the on-axis area and the plurality of off-axis areas, polarization states of the illumination light in the plurality of off-axis areas on the pupil plane being substantially linear polarization; and

projecting an image of the pattern illuminated with the illumination light onto the substrate by the projection system,

wherein the light amount distribution on the pupil plane is generated by a formation optical system arranged in the illumination system and at an incident side of an optical integrator, and

a polarization direction of the illumination light which passes through at least one of the plurality of off-axis areas is changed by a polarization setting member so that the polarization direction at any off-axis area on the pupil plane is substantially perpendicular to a radial direction extending from the optical axis to that off-axis area the polarization setting member being arranged in the illumination system and at the incident side of the optical integrator.

2. The exposure method according to claim 1, wherein

the plurality of off-axis areas include an even number of areas at approximately a same distance from the optical axis.

3. The exposure method according to claim 1, wherein

the on-axis area and two of the plurality of off-axis areas are arranged on a same straight line passing through the optical axis.

4. A device manufacturing method, comprising:

exposing a substrate by the exposure method as recited in claim 1;

developing the exposed substrate; and

processing the developed substrate.

5. The exposure method according to claim 1, wherein

the plurality of off-axis areas are separated from each other by the area other than the on-axis area and the plurality of off-axis areas, on the pupil plane of the illumination system.

6. The exposure method according to claim 5, wherein

respective distances between centers of the plurality of off-axis areas and the optical axis are substantially equal to each other, on the pupil plane of the illumination system.

7. The exposure method according to claim 6, wherein

the centers of two of the plurality of off-axis areas are arranged on a same straight line passing through the optical axis, on the pupil plane.

8. The exposure method according to claim 1, wherein

the formation optical system includes a deflecting member used to generate the light amount distribution, and a movable optical member different from the deflecting member.

9. The exposure method according to claim 8, wherein

the deflecting member is changed with a different deflecting member in order to generate a different light amount distribution from the light amount distribution.

10. The exposure method according to claim 1, wherein

the formation optical system includes a plurality of optical members, and changes the light amount distribution by exchange of a first optical member of the plurality of optical members and/or movement of a second optical member of the plurality of optical members, different from the first optical member.

11. The exposure method according to claim 1, wherein

the polarization setting member is arranged between a member, arranged at a most upstream side in the formation optical system, and the optical integrator.

12. The exposure method according to claim 1, wherein

the formation optical system includes a diffractive optical element, and

the polarization setting member is arranged between the diffractive optical element and the optical integrator.

13. The exposure method according to claim 12, wherein

the formation optical system includes a movable member arranged at an exit side of the diffractive optical element and movable along the optical axis, and the polarization setting member is arranged between the diffractive optical element and the movable member.

14. The exposure method according to claim 1, wherein

the polarization setting member includes at least one of a ½

wave plate and a ¼

wave plate.

15. The exposure method according to claim 1, wherein

the formation optical system includes a distribution changing member which can change the light amount distribution to a plurality of distributions different from each other, and

the polarization setting member is arranged between the distribution changing member and the optical integrator.

16. The exposure method according to claim 15, wherein

the distribution changing member includes a first diffractive optical element and a second diffractive optical element which have diffraction characteristics different from each other, and

the first diffractive optical element and the second diffractive optical element are arranged to be mutually exchanged.

17. The exposure method according to claim 15, wherein

the distribution changing member includes a movable optical member which is movable along the optical axis.

18. The exposure apparatus according to claim 17, wherein

the formation optical system includes a position changing member which can change a positional relationship of the plurality of off-axis areas with respect to the optical axis.

19. The exposure method according to claim 1, wherein

the formation optical system includes a position changing member which can change a positional relationship of the plurality of off-axis areas with respect to the optical axis, and

the polarization setting member is arranged at an upstream side of the position changing member.

20. The exposure method according to claim 18, wherein

the position changing member includes a movable optical member which is movable along the optical axis.

21. The exposure method according to claim 1, wherein

the optical integrator includes a fly-eye lens of which an exit surface is arranged so as to be substantially coincident with the pupil plane.

22. The exposure method according to claim 1, wherein

the optical integrator includes a fly-eye lens of which an exit surface is arranged so as to be substantially coincident with an optical Fourier transform plane with respect to a plane on which the pattern is arranged.

23. An exposure apparatus, comprising:

an illumination system which illuminates a pattern with illumination light; and

a projection system which projects an image of the pattern illuminated with the illumination light onto a substrate, wherein

the illumination system comprises;

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

a formation optical system which is arranged in the optical path on an incident side of the optical integrator, and which generates a light amount distribution on a pupil plane of the illumination system, in which an amount of light is larger in an on-axis area substantially including an optical axis and in a plurality of off-axis areas arranged away from the optical axis than in an area other than the on-axis area and the plurality of off-axis areas, and

a polarization setting member which is arranged in the optical path on the incident side of the optical integrator, and which changes a polarization direction of the illumination light which passes through at least one of the plurality of off-axis areas so that the polarization direction at any off-axis area on the pupil plane is substantially coincident with a circumference direction substantially centered around the optical axis perpendicular to a radial direction extending from the optical axis to that off-axis area, a polarization state of the illumination light in the plurality of off-axis areas being substantially linear polarization.

24. The exposure apparatus according to claim 23, wherein

the plurality of off-axis areas include an even number of areas at approximately a same distance from the optical axis.

25. The exposure apparatus according to claim 23, wherein

the on-axis area and two of the plurality of off-axis areas are arranged on a same straight line passing through the optical axis.

26. The exposure apparatus according to claim 23, wherein

the formation optical system can change the light amount distribution by movement of an optical element and/or by exchange of optical elements.

27. A device manufacturing method, comprising:

exposing a substrate with the exposure apparatus as recited in claim 23;

developing the exposed substrate; and

processing the developed substrate.

28. The exposure apparatus according to claim 23, wherein

the plurality of off-axis areas are separated from each other by the area other than the on-axis area and the plurality of off-axis areas, on the pupil plane of the illumination system.

29. The exposure apparatus according to claim 28, wherein

respective distances between centers of the plurality of off-axis areas and the optical axis are substantially equal to each other, on the pupil plane of the illumination system.

30. The exposure apparatus according to claim 29, wherein

the centers of two of the plurality of off-axis areas are arranged on a same straight line passing through the optical axis, on the pupil plane.

31. The exposure apparatus according to claim 23, wherein

the formation optical system includes a deflecting member used to generate the light amount distribution, and a movable optical member different from the deflecting member.

32. The exposure apparatus according to claim 31, wherein

the deflecting member is changed with a different deflecting member in order to generate a different light amount distribution from the light amount distribution.

33. The exposure apparatus according to claim 23, wherein

the formation optical system includes a plurality of optical members, and changes the light amount distribution by at least one of exchanging a first optical member of the plurality of optical members and moving a second optical member of the plurality of optical members, different from the first optical member.

34. The exposure apparatus according to claim 23, wherein

the polarization setting member is arranged between a member, arranged at a most upstream side in the formation optical system, and the optical integrator.

35. The exposure apparatus according to claim 23, wherein

the formation optical system includes a diffractive optical element, and

the polarization setting member is arranged between the diffractive optical element and the optical integrator.

36. The exposure apparatus according to claim 35, wherein

the formation optical system includes a movable member arranged at an exit side of the diffractive optical element and movable along the optical axis, and

the polarization setting member is arranged between the diffractive optical element and the movable member.

37. The exposure apparatus according to claim 23, wherein

the polarization setting member includes at least one of a ½

wave plate and a ¼

wave plate.

38. The exposure apparatus according to claim 23, wherein

the formation optical system includes a distribution changing member which can change the light amount distribution to a plurality of distributions different from each other, and

the polarization setting member is arranged between the distribution changing member and the optical integrator.

39. The exposure apparatus according to claim 38, wherein

the distribution changing member includes a first diffractive optical element and a second diffractive optical element which have diffraction characteristics different from each other, and

the first diffractive optical element and the second diffractive optical element are arranged to be mutually exchanged.

40. The exposure apparatus according to claim 38, wherein

the distribution changing member includes a movable member which is movable along the optical axis.

41. The exposure apparatus according to claim 23, wherein

the optical integrator includes a fly-eye lens of which an exit surface is arranged so as to be substantially coincident with the pupil plane.

42. The exposure apparatus according to claim 23, wherein

the optical integrator includes a fly-eye lens of which an exit surface is arranged so as to be substantially coincident with an optical Fourier transform plane with respect to a plane on which the pattern is arranged.