Illumination optical system, exposure apparatus, and exposure method with polarized state fluctuation correcting device
First Claim
1. An illumination optical system for use with an exposure apparatus including a projection optical system and that illuminates a pattern onto an illuminated surface with light including a predetermined polarized state supplied from a light source, the illumination optical system comprising:
- a light directing device that directs the light from the light source to the illuminated surface, the light directing device being positioned in a light path between the light source and the illuminated surface;
a pupil intensity distribution forming device that forms a predetermined light intensity distribution at a position conjugate to a pupil of the projection optical system or a position adjacent thereto;
a pupil intensity distribution changing device that changes at least one of a shape and a size of the predetermined light intensity distribution, and that changes at least one of the shape and the size of the predetermined light intensity distribution in accordance with pattern characteristics of the pattern;
a polarized state fluctuation correcting device that corrects fluctuations in the polarized state on the illuminated surface, the polarized state fluctuation correcting device being positioned in the light path between the light source and the illuminated surface; and
a polarized state changing device that is positioned in the light path between the light source and the illuminated surface and changes the polarized state of the light that illuminates the illuminated surface in accordance with at least one of the shape and the size of the predetermined light intensity distribution.
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Abstract
An illumination optical system for, when installed in an exposure system, realizing a suitable illumination condition by varying the polarized state of the illumination light according to the pattern characteristics of the mask while suppressing the loss of the intensity of the light. The illumination optical system has a light source unit for supplying a linearly polarized light for illuminating surfaces to be illuminated therewith, and a polarized state changing device for changing the polarized state of the illuminating light from a predetermined polarized state to a nonpolarized state and vice versa. The polarized state changing device is arranged in the optical path between the light source unit and the surfaces to be illuminated. The polarized state changing device can be removed from the illumination optical path and has a depolarizer for selectively depolarizing the incident linearly polarized light.
18 Citations
30 Claims
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1. An illumination optical system for use with an exposure apparatus including a projection optical system and that illuminates a pattern onto an illuminated surface with light including a predetermined polarized state supplied from a light source, the illumination optical system comprising:
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a light directing device that directs the light from the light source to the illuminated surface, the light directing device being positioned in a light path between the light source and the illuminated surface; a pupil intensity distribution forming device that forms a predetermined light intensity distribution at a position conjugate to a pupil of the projection optical system or a position adjacent thereto; a pupil intensity distribution changing device that changes at least one of a shape and a size of the predetermined light intensity distribution, and that changes at least one of the shape and the size of the predetermined light intensity distribution in accordance with pattern characteristics of the pattern; a polarized state fluctuation correcting device that corrects fluctuations in the polarized state on the illuminated surface, the polarized state fluctuation correcting device being positioned in the light path between the light source and the illuminated surface; and a polarized state changing device that is positioned in the light path between the light source and the illuminated surface and changes the polarized state of the light that illuminates the illuminated surface in accordance with at least one of the shape and the size of the predetermined light intensity distribution. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28)
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29. An illumination optical system that illuminates an illuminated surface with light including a predetermined polarized state supplied from a light source, comprising:
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a light directing device that directs the light from the light source to the illuminated surface, the light directing device being positioned in a light path between the light source and the illuminated surface; and a polarized state fluctuation correcting device that corrects fluctuations in the polarized state on the illuminated surface, which originates in a light transmissive member formed by a cubic system crystal material in the light directing device, the light transmissive member is positioned in the light path between the light source and the illuminated surface, the polarized state fluctuation correcting device being positioned in the light path between the light source and the illuminated surface, wherein the light transmissive member includes a rectangular prism as a rear surface reflection mirror, an incident surface and an exit surface of the rectangular prism are configured to substantially match a crystal plane {100}, and a reflection surface of the rectangular prism is configured to substantially match a crystal plane {110}.
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30. An illumination optical system that illuminates an illuminated surface with light including a predetermined polarized state supplied from a light source, comprising:
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a light directing device that directs the light from the light source to the illuminated surface, the light directing device being positioned in a light path between the light source and the illuminated surface; and a polarized state fluctuation correcting device that corrects fluctuations in the polarized state on the illuminated surface, which originates in a light transmissive member formed by a cubic system crystal material in the light directing device, the light transmissive member is positioned in the light path between the light source and the illuminated surface, the polarized state fluctuation correcting device being positioned in the light path between the light source and the illuminated surface, wherein the light transmissive member includes a plane parallel plate for moving light entering along the optical axis in parallel, the light transmissive member being provided in the light path and inclinable with respect to the optical axis, and the optical axis of the plane parallel plate is configured to substantially match the crystal orientation <
100>
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Specification