Polarizer device for generating a defined spatial distribution of polarization states

• US 20060028706A1
• Filed: 07/06/2005
• Published: 02/09/2006
• Est. Priority Date: 07/08/2004
• Status: Abandoned Application

• Current Assignee: Carl Zeiss AG (Carl-Zeiss-Stiftung)
• Original Assignee: Carl Zeiss AG (Carl-Zeiss-Stiftung)
• Inventors: Totzeck, Michael, Gruner, Toralf, Harnisch, Wolfgang, Schuster, Karl-Heinz, Scheruebl, Thomas, Stroessner, Ulrich, Feldman, Heiko, Greif-Wuestenbecker, Joern N.
• Application Number:
  US11/174,489
• Publication Number:
  US 20060028706A1
• Time in Patent Office: Days
• US Class Current: 359/238
• CPC Class Codes: G02B 27/286 for controlling or changing the state of polarisation, e.g. transforming one polarisation state into another G02B5/3083 takes precedence; light guide coupling means utilising polarising elements G02B6/34
• CPC Class Codes: G02B 27/288 Filters employing polarising elements, e.g. Lyot or Solc filters G02B5/3016 takes precedence
• CPC Class Codes: G02B 5/3041 comprising multiple thin layers, e.g. multilayer stacks
• CPC Class Codes: G02B 5/3091 for use in the UV
• 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 7/70566 Polarisation control

Abstract

A polarizer device, for converting an entry light beam into an exit light beam with a defined spatial distribution of polarization states, has an angle varying input device for receiving the entry light beam and for generating a first light beam with a predeterminable first angular distribution of light rays; an angle-selectively active polarization influencing device for receiving the first light beam and for converting the first light beam into a second light beam according to a defined angle function of the polarization state variation; and an angle varying output device for receiving the second light beam and for generating the exit light beam with a second angular distribution from the second light beam. In particular, polarization states with a radial or tangential polarization can be provided cost-effectively in this way.

Claims

1. A polarizer device for converting an entry light beam into an exit light beam with a defined spatial distribution of polarization states, comprising:

an angle varying input device for receiving the entry light beam and for generating a first light beam with a predeterminable first angular distribution of light rays;

an angle-selectively active polarization influencing device for receiving the first light beam and for converting the first light beam into a second light beam according to a defined angle function of the polarization state variation; and

an angle varying output device for receiving the second light beam and for generating the exit light beam with a second angular distribution from the second light beam.

2. The polarizer device as claimed in claim 1, wherein the angle-selectively active polarization influencing device comprises at least one polarizing layer, which is arranged on a layer carrying substrate.

3. The polarizer device as claimed in claim 2, wherein the polarizing layer is designed as a polarization beam splitter layer.

4. The polarizer device as claimed in claim 2, wherein the polarizing layer is formed by a multiple layer system of stacked layers with dielectric materials of different refractive indices.

5. The polarizer device as claimed in claim 3, wherein the polarization splitter layer is designed so that it has a higher transmissivity for p-polarized light than for s-polarized light, at least in a predominant part of an angle of incidence range encountered during exposure to light with the first angular distribution.

6. The polarizer device as claimed in claim 5, wherein the polarization splitter layer is used to generate radial polarization.

7. The polarizer device as claimed in claim 3, wherein the polarization splitter layer is designed so that it has a higher transmissivity for s-polarized light than for p-polarized light, at least in a predominant part of an angle of incidence range encountered during exposure to light with the first angular distribution.

8. The polarizer device as claimed in claim 7, wherein the polarization splitter layer is used to generate tangential polarization.

9. The polarizer device as claimed in claim 3, wherein the polarization splitter layer has a layer structure in which optical layer thicknesses of some or all stacked high-index and low-index dielectric layers lie between about 20% and about 60% of a working wavelength λ

0 intended for the polarization splitter layer.

10. The polarizer device as claimed in claim 2, wherein the angle-selectively active polarization influencing device is constructed by using form birefringence.

11. The polarizer device as claimed in claim 3, wherein the polarization splitter layer is constructed using a periodic structure of stacked layers of differently refracting dielectric materials, in which a periodicity length of the periodic structure is small compared with a working wavelength λ

0 intended for the polarization splitter layer.

12. The polarizer device as claimed in claim 2, wherein the polarization influencing device contains a polarizing layer in combination with a lateral structure on at least one of its surfaces.

13. The polarizer device as claimed in claim 12, wherein the lateral structure has form birefringent grating structures, which have a lateral spacing from one another which is less than a working wavelength λ

0 intended for the lateral structure.

14. The polarizer device as claimed in claim 13, wherein the lateral spacing of the grating structures is less than 70% of the working wavelength.

15. The polarizer device as claimed in claim 2, wherein a substrate surface of the layer carrying substrate, on which the polarized layer is provided, is essentially flat.

16. The polarizer device as claimed in claim 2, wherein the substrate has the form of a plane-parallel plate.

17. The polarizer device as claimed in claim 2, wherein the layer carrying substrate is a lens with at least one convexly or concavely curved substrate surface, on which the polarizing layer is applied.

18. The polarizer device as claimed in claim 1, wherein the input device is designed so that the first angular distribution has a first numerical aperture NA1<

0.2.

19. The polarizer device as claimed in claim 1, wherein the input device is designed so that the first angular distribution generates an angle of incidence spectrum at the polarization influencing device, which includes angles of incidence at which a polarization varying effect of the polarization influencing device is maximal.

20. The polarizer device as claimed in claim 1, wherein the polarizer device is adapted to an entry light beam which has a numerical aperture NAE<

0.1 on the entry side.

21. The polarizer device as claimed in claim 1, wherein the polarizer device generates an exit light beam with a numerical aperture NAA<

0.1 on the exit side.

22. The polarizer device as claimed in claim 1, wherein the input device has a positive refractive power and defines a rear focal plane, and the output device has a positive refractive power and defines a front focal plane, which essentially coincides in a focal region with the rear focal plane of the input device.

23. The polarizer device as claimed in claim 22, wherein the polarization influencing device is arranged outside the focal region.

24. The polarizer device as claimed in claim 23, wherein the polarization influencing device is arranged in the optical path upstream of the focal region.

25. The polarizer device as claimed in claim 23, wherein an aperture is provided in the focal region.

26. The polarizer device as claimed in claim 1, wherein the input device is designed so that the first light beam striking the polarization influencing device has an essentially spherical wavefront.

27. The polarizer device as claimed in claim 1, wherein the input device contains at least one aspherical surface, and is designed so that the first light beam striking the polarization influencing device has an aspherical wavefront.

28. The polarizer device as claimed in claim 1, wherein the input device and the output device respectively contain at least one cylindrical lens.

29. The polarizer device as claimed in claim 1, wherein the input device and the output device respectively contain at least one rotationally symmetric asphere.

30. The polarizer device as claimed in claim 1, further comprising a manipulation device for moving the polarization influencing device relative to the input device and the output device.

31. The polarizer device as claimed in claim 30, wherein the manipulation device is designed so that the polarization influencing device can be tilted in relation to the optical axis, about a tilting axis which extends transversely to the optical axis.

32. The polarizer device as claimed in claim 30, wherein the manipulation device is designed so that the polarization influencing device can be displaced along the optical axis.

33. The polarizer device as claimed in claim 30, wherein the manipulation device is designed so that the polarization influencing device can be displaced transversely with respect to the optical axis.

34. The polarizer device as claimed in claim 30, wherein the manipulation device is designed so that the polarization influencing device can be rotated about a rotation axis extending parallel to the optical axis.

35. The polarizer device as claimed in claim 30, wherein the manipulation device comprises a changer device, which is designed so that the polarization influencing device can be inserted selectively into the optical path between the input device and the output device, or can be removed from the optical path.

36. The polarizer device as claimed in claim 1, wherein the polarization influencing device is used in transmission, so that the polarization distribution of the exit light beam is determined by the properties of the transmitted radiation.

37. The polarizer device as claimed in claim 1, wherein the polarization influencing device is used in reflection, so that the polarization distribution of the exit light beam is determined by the properties of the reflected radiation.

38. The polarizer device as claimed in claim 1, wherein the polarizer device is provided with at least one further polarization influencing device for modifying the polarization distribution.

39. The polarizer device as claimed in claim 38, wherein the further polarization influencing device is a polarization rotator.

40. The polarizer device as claimed in claim 39, wherein the polarization rotator is designed for a rotation of polarization states through 90°

.

41. The polarizer device as claimed in claim 39, wherein a plate of an optically active material is provided as the polarization rotator, which is inserted or can be inserted behind the polarization influencing device in the beam path.

42. An illumination system for a microlithography projection exposure apparatus for illuminating an illumination field with the light from a primary light source, wherein a polarizer device as claimed in claim 1 is arranged between the light source and the illumination field.

43. An illumination system for a microlithography projection exposure apparatus for illuminating an illumination field with the light from a primary light source, comprising:

a pupil shaping unit for receiving light from the primary light source and for generating a two-dimensional intensity distribution in a pupil shaping surface of the illumination system;

an angle varying input device for receiving an entry light beam coming from the pupil shaping surface and for generating a first light beam with a predeterminable first angular distribution of light rays;

an angle-selectively active polarization influencing device for receiving the first light beam and for converting the first light beam into a second light beam according to a defined angle function of the polarization state variation; and

an angle varying output device for receiving the second light beam and for generating an exit light beam traveling to the illumination field with a second angular distribution from the second light beam.

44. The illumination system as claimed in claim 43, wherein the input device comprises a light mixing device for mixing and homogenizing the light in a field surface of the illumination system, which follows the light mixing device, and the polarization influencing device is arranged in the vicinity of this field surface.

45. The illumination system as claimed in claim 44, wherein the light mixing device comprises a rod integrator with a light entry surface and a light exit surface, and the polarization influencing device comprises a polarizing layer which is arranged on the light exit surface.

46. The illumination system as claimed in claim 43, wherein the polarization influencing device comprises at least one polarizing layer, which is arranged on a layer carrying substrate.

47. The illumination system as claimed in claim 43, wherein the polarization influencing device comprises a plane plate of a transparent material, in which a polarizing layer is applied on at least one plate surface.

48. The illumination system as claimed in claim 46 wherein the polarizing layer is designed as a polarization beam splitter layer.

49. The illumination system as claimed in claim 43, wherein the polarization influencing device is interchangeable.

50. The illumination system as claimed in claim 44 wherein the light mixing device comprises at least one fly'"'"'s eye condenser.