Illumination optical system, exposure apparatus, and exposure method with polarized switching device
First Claim
1. An illumination optical system that illuminates an illuminated surface with light from a light source that provides linearly polarized light, comprising:
- a polarized state switching device positioned in a light path between the light source and the illuminated surface, the polarized state switching device switches a polarized state of the light that illuminates the illuminated surface between a predetermined linearly polarized state and a nonpolarized state while controlling a loss of light amount, and varies a polarization plane of the predetermined linearly polarized light.
1 Assignment
0 Petitions
Accused Products
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.
-
Citations
58 Claims
-
1. An illumination optical system that illuminates an illuminated surface with light from a light source that provides linearly polarized light, comprising:
a polarized state switching device positioned in a light path between the light source and the illuminated surface, the polarized state switching device switches a polarized state of the light that illuminates the illuminated surface between a predetermined linearly polarized state and a nonpolarized state while controlling a loss of light amount, and varies a polarization plane of the predetermined linearly polarized light. - 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)
-
29. An illumination optical system that illuminates an illuminated surface with light from a light source that provides linearly polarized light, comprising:
-
a polarized state switching device positioned in a light path between the light source and the illuminated surface, the polarized state switching device switches a polarized state of the light that illuminates the illuminated surface between a predetermined linearly polarized state and a nonpolarized state while controlling a loss of light amount, wherein the polarized state switching device comprises a depolarizer that unpolarizes the incident linearly polarized light, the depolarizer being insertable into and removable from an illumination light path. - View Dependent Claims (30, 31, 32)
-
-
33. An illumination optical system that illuminates an illuminated surface with light from a light source that provides linearly polarized light, comprising:
-
a polarized state switching device positioned in a light path between the light source and the illuminated surface, the polarized state switching device switches a polarized state of the light that illuminates the illuminated surface between a predetermined linearly polarized state and a nonpolarized state while controlling a loss of light amount, wherein the polarized state switching device comprises a depolarizer that unpolarizes the incident linearly polarized light, and when switching the polarized state of the light that illuminates the illuminated surface, light in a polarized state that has not been unpolarized by the depolarizer is directed to the depolarizer. - View Dependent Claims (34, 35)
-
-
36. An illumination optical system that illuminates an illuminated surface with light from a light source that provides linearly polarized light, comprising:
-
a polarized state switching device positioned in a light path between the light source and the illuminated surface, the polarized state switching device switches a polarized state of the light that illuminates the illuminated surface between a predetermined linearly polarized state and a nonpolarized state while controlling a loss of light amount; an illumination pupil distribution forming device that forms a predetermined light intensity distribution on or adjacent to a pupil plane of the illumination optical system; a changing device that changes at least one of a shape and a size of the predetermined light intensity distribution; and a light direction optical system that directs a light beam including the predetermined light intensity distribution to the illuminated surface. - View Dependent Claims (37, 38)
-
-
39. An illumination optical system that illuminates an illuminated surface with light from a light source that provides linearly polarized light, comprising:
-
a polarized state switching device positioned in a light path between the light source and the illuminated surface, the polarized state switching device switches a polarized state of the light that illuminates the illuminated surface between a predetermined linearly polarized state and a nonpolarized state while controlling a loss of light amount, wherein S1 and S2 components of a Stokes parameter of the light satisfy the below conditions in the nonpolarized state;
|S1|≦
0.1
|S2|≦
0.1.
-
-
40. An exposure method, comprising:
-
illuminating a mask through an illumination optical system; and exposing an image of a pattern on the mask onto the photosensitive substrate positioned on the illuminated surface, wherein the illumination optical system illuminates an illuminated surface with light from a light source that provides linearly polarized light, the illumination optical system comprising; a polarized state switching device positioned in a light path between the light source and the illuminated surface, the polarized state switching device switches a polarized state of the light that illuminates the illuminated surface between a predetermined linearly polarized state and a nonpolarized state while controlling a loss of light amount. - View Dependent Claims (41, 42, 43, 44, 45)
-
-
46. An illumination optical system that illuminates an illuminated surface with light from a light source that provides linearly polarized light, comprising:
-
a polarized state switching device positioned in a light path between the light source and the illuminated surface, the polarized state switching device switches a polarized state of the light that illuminates the illuminated surface between a predetermined linearly polarized state and a nonpolarized state while controlling a loss of light amount; a polarization monitor positioned in a downstream light path of the polarized state switching device to detect the polarized state of the light, and a controller that controls the polarized state switching device in response to an output from the polarization monitor.
-
-
47. An exposure method for exposing a pattern on a mask positioned at a first plane onto a photosensitive substrate positioned at a second plane, comprising:
-
providing linearly polarized light; illuminating the mask with the provided light; exposing the pattern on the illuminated mask onto the photosensitive substrate; and switching a polarized state of the light on the second plane between a predetermined linearly polarized state and a nonpolarized state while controlling a loss of a light amount. - View Dependent Claims (48, 49)
-
-
50. An illumination optical system that illuminates an illuminated surface with light from a light source that provides linearly polarized light, comprsing:
-
a polarized state switching device positioned in a light path between the light source and the illuminated surface, the polarized state switching device switches a polarized state of the light that illuminates the illuminated surface between a predetermined polarized state and a nonpolarized state while controlling a loss of light amount; a polarization monitor positioned in a downstream light path of the polarized state switching device to detect the polarized state of the light; and a controller that controls the polarized state switching device in response to an output from the polarization monitor. - View Dependent Claims (51, 52, 53, 54, 55, 56, 57, 58)
-
Specification