Catadioptric projection objective

Abstract

A reflection mirror assembly for use in a catadioptric imaging optical system includes two curved reflection mirrors, each including a reflection surface expressed by equation (a), where y represents height in a direction perpendicular to the optical axis, z represents distance (sag amount) along the optical axis from a tangent plane at a vertex of the reflection surface to a position on the reflection surface at height y, r represents a vertex curvature radius, and R represents a conical coefficient; z =( y 2 /r )/[1+{1−(1+κ)· y 2 /r 2 } 1/2 ]  (a), wherein −1<k<0.

1 .- 162 . (canceled) 
     
     
         163 . A reflection mirror assembly for use in a catadioptric imaging optical system, the assembly comprising:
 two curved reflection mirrors, each including a reflection surface expressed by equation (a), where y represents height in a direction perpendicular to the optical axis, z represents distance (sag amount) along the optical axis from a tangent plane at a vertex of the reflection surface to a position on the reflection surface at height y, r represents a vertex curvature radius, and κ represents a conical coefficient;
     z =( y   2   /r )/[1+{1−(1+κ)· y   2   /r   2 } 1/2 ]  (a),
 
   wherein −1<k<0.   
     
     
         164 . The assembly according to  claim 163 , wherein the two curved reflection mirrors include identically shaped reflection mirrors. 
     
     
         165 . A catadioptric imaging optical system that forms an image of a first plane on a second plane, the catadioptric imaging optical system comprising:
 a first imaging system which forms a first intermediate image of the first plane based on light from the first plane;   a second imaging system which includes two concave reflection mirrors and which forms a second intermediate image of the first plane based on light from the first intermediate image; and   a third imaging system which forms a final image of the first plane on the second plane based on light from the second intermediate image;   wherein at least one of the two concave reflection mirrors includes a reflection surface expressed by equation (a), where y represents height in a direction perpendicular to the optical axis, z represents distance (sag amount) along the optical axis from a tangent plane at a vertex of the reflection surface to a position on the reflection surface at height y, r represents a vertex curvature radius, and κ represents a conical coefficient;
     z =( y   2   /r )[1+{1−(1+κ)· y   2   /r   2 } 1/2 ]  (a),
 
   wherein −1<k<0.   
     
     
         166 . The catadioptric imaging optical system according to  claim 165 , wherein one focal point of the reflection surface is located on or near a pupil position of the first imaging system or third imaging system and the other focal point of the reflection surface is located on or near a pupil position of the second imaging system. 
     
     
         167 . The catadioptric imaging optical system according to  claim 166 , wherein the two concave reflection mirrors each include a reflection surface. 
     
     
         168 . The catadioptric imaging optical system according to  claim 167 , wherein the two concave reflection mirrors include identically shaped reflection surfaces. 
     
     
         169 . The catadioptric imaging optical system according to  claim 165 , wherein the first imaging system and the third imaging system are each a dioptric system that is free from a reflection mirror. 
     
     
         170 . The catadioptric imaging optical system according to  claim 169 , wherein the second imaging system consists of only the two concave reflection mirrors. 
     
     
         171 . The catadioptric imaging optical system according to  claim 165 , wherein the catadioptric imaging optical system is an off-axis field catadioptric imaging optical system which forms an image of the first plane on the second plane only in a region distant from an optical axis. 
     
     
         172 . The catadioptric imaging optical system according to  claim 165 , wherein the first to third imaging systems are arranged coaxially with one another. 
     
     
         173 . (canceled) 
     
     
         174 . The catadioptric imaging optical system according to  claim 165 , wherein at least one of the two concave reflection mirrors includes an opening portion which is for passage of focusing light and is supported at a plurality of positions distanced from an optical axis by a substantially equal distance. 
     
     
         175 . The catadioptric imaging optical system according to  claim 174 , wherein at least one of the two concave reflection mirrors is supported at a plurality of positions that are substantially rotationally symmetric with respect to the optical axis. 
     
     
         176 . The catadioptric imaging optical system according to  claim 165 , wherein at least one of the two concave reflection mirrors includes an effective reflection surface corresponding to part of a curved surface that is substantially rotationally symmetric with respect to an optical axis. 
     
     
         177 . An exposure apparatus comprising:
 the catadioptric imaging optical system according to  claim 165  which projects an image of the pattern onto a photosensitive substrate set as the second plane based on light from a predetermined pattern set as the first plane.   
     
     
         178 . A device manufacturing method comprising:
 exposing the predetermined pattern onto the photosensitive substrate using the exposure apparatus according to  claim 177 ;   developing the photosensitive substrate onto which the pattern has been transferred;   forming on a surface of the photosensitive substrate a mask layer shaped in correspondence with the pattern; and   processing the surface of the photosensitive substrate through the mask layer.   
     
     
         179 . (canceled) 
     
     
         180 . An off-axis field catadioptric imaging optical system that forms an image of a first plane on a second plane only in a region distant from an optical axis, the off-axis field catadioptric imaging optical system comprising:
 two curved reflection mirrors and a plurality of dioptric elements;   wherein at least one of the two curved reflection mirrors includes a prolate spheroidal shaped reflection surface expressed by equation (a), where y represents height in a direction perpendicular to the optical axis, z represents distance (sag amount) along the optical axis from a tangent plane at a vertex of the reflection surface to a position on the reflection surface at height y, r represents a vertex curvature radius, and κ represents a conical coefficient;
     z =( y   2   /r )/[1+{1−(1+κ)· y   2   /r   2 } 1/2 ]  (a),
 
   wherein −1<k<0.   
     
     
         181 . The catadioptric imaging optical system according to  claim 180 , wherein the two curved reflection mirrors and the plurality of dioptric elements are arranged coaxially with the optical axis. 
     
     
         182 . The catadioptric imaging optical system according to  claim 181 , wherein the two curved reflection mirrors are concave reflection mirrors. 
     
     
         183 . The catadioptric imaging optical system according to  claim 182 , wherein the two concave reflection mirrors each include the reflection surface. 
     
     
         184 . The catadioptric imaging optical system according to  claim 183 , wherein the two curved reflection mirrors include identically shaped reflection surfaces. 
     
     
         185 . (canceled) 
     
     
         186 . The catadioptric imaging optical system according to  claim 180 , wherein at least one of the two concave reflection mirrors includes an opening portion which is for passage of focusing light and is supported at a plurality of positions distanced from the optical axis by a substantially equal distance. 
     
     
         187 . The catadioptric imaging optical system according to  claim 186 , wherein at least one of the two concave reflection mirrors is supported at a plurality of positions that are substantially rotationally symmetric with respect to the optical axis. 
     
     
         188 . The catadioptric imaging optical system according to  claim 180 , wherein at least one of the two concave reflection mirrors includes an effective reflection surface corresponding to part of a curved surface that is substantially rotationally symmetric with respect to an optical axis. 
     
     
         189 . An exposure apparatus comprising:
 the catadioptric imaging optical system according to  claim 180  which projects an image of the pattern onto a photosensitive substrate set as the second plane based on light from a predetermined pattern set as the first plane.   
     
     
         190 . A device manufacturing method comprising:
 exposing the predetermined pattern onto the photosensitive substrate using the exposure apparatus according to  claim 189 ;   developing the photosensitive substrate onto which the pattern has been transferred;   forming on a surface of the photosensitive substrate a mask layer shaped in correspondence with the pattern; and   processing the surface of the photosensitive substrate through the mask layer.   
     
     
         191 . A reflection mirror for use in a catadioptric imaging optical system including a first imaging system which forms a first intermediate image of a first plane based on light from the first plane, a second imaging system which forms a second intermediate image of the first plane based on light from the first intermediate image, and a third imaging system which forms a final image of the first plane on the second plane based on light from the second intermediate image, the reflection mirror comprising:
 at least one of two concave reflection mirrors arranged in the second imaging system and including a prolate spheroidal shaped reflection surface expressed by equation (a), where y represents height in a direction perpendicular to the optical axis, z represents distance (sag amount) along the optical axis from a tangent plane at a vertex of the reflection surface to a position on the reflection surface at height y, r represents a vertex curvature radius, and κ represents a conical coefficient;
     z =( y   2   /r )/[1+{1−(1+κ)· y   2   /r   2 } 1/2 ]  (a),
 
   wherein −1<k<0.   
     
     
         192 . The reflection mirror according to  claim 191 , wherein one focal point of the reflection surface is located on or near a pupil position of the first imaging system or third imaging system and the other focal point of the reflection surface is located on or near a pupil position of the second imaging system. 
     
     
         193 . (canceled) 
     
     
         194 . The reflection mirror according to  claim 191 , further comprising an opening portion which is for passage of focusing light, wherein the reflection mirror is supported at a plurality of positions distanced from an optical axis by a substantially equal distance. 
     
     
         195 . The reflection mirror according to  claim 194 , wherein the reflection mirror is supported at a plurality of positions that are substantially rotationally symmetric with respect to the optical axis. 
     
     
         196 . The reflection mirror according to  claim 194 , wherein the opening portion is formed at a location distanced from the optical axis. 
     
     
         197 . A reflection mirror for use in an off-axis catadioptric imaging optical system that forms an image of a first plane on a second plane only at a region distanced from an optical axis, with the catadioptric imaging optical system including two curved reflection mirrors and a plurality of dioptric elements, the reflection mirror comprising:
 a reflection surface expressed by equation (a), where y represents height in a direction perpendicular to the optical axis, z represents distance (sag amount) along the optical axis from a tangent plane at a vertex of the reflection surface to a position on the reflection surface at height y, r represents a vertex curvature radius, and κ represents a conical coefficient;
     z =( y   2   /r )/[1+{1−(1+κ)· y   2   /r   2 } 1/2 ]  (a),
 
   wherein the reflection mirror is at least one of the two curved reflection mirrors of the catadioptric imaging optical system,   wherein −1<k<0.   
     
     
         198 . The reflection mirror according to  claim 197 , wherein the two curved reflection mirrors and the plurality of plurality of dioptric elements are arranged coaxially with the optical axis. 
     
     
         199 . The reflection mirror according to  claim 197 , wherein the two curved reflection mirrors are concave reflection mirrors. 
     
     
         200 . (canceled) 
     
     
         201 . The reflection mirror according to  claim 197 , further comprising:
 an opening portion which is for passage of focusing light, wherein the reflection mirror is supported at a plurality of positions distanced from the optical axis by a substantially equal distance.   
     
     
         202 . The reflection mirror according to  claim 201 , wherein the reflection mirror is supported at a plurality of positions that are substantially rotationally symmetric with respect to the optical axis. 
     
     
         203 . The reflection mirror according to  claim 201 , wherein the opening portion is formed at a location distanced from the optical axis.