Polarization-modulating element, illumination optical apparatus, exposure apparatus, and exposure method

Abstract

A polarization-modulating element for modulating a polarization state of incident light into a predetermined polarization state, the polarization-modulating element being made of an optical material with optical activity and having a circumferentially varying thickness profile.

What is claimed is: 
     
         1 . An illumination optical apparatus for illuminating a surface to be illuminated, based on illumination radiation supplied from a radiation source, the illumination optical apparatus comprising:
 a polarization modulating element, which is arranged in an optical path of the illumination radiation, which is made of an optical material with optical activity, and which has a circumferentially varying thickness; and   a movable optical element arranged in an optical path between the polarization modulating element and the surface to be illuminated.   
     
     
         2 . A device manufacturing method comprising the steps of:
 projecting a predetermined pattern onto a photosensitive substrate, using the illumination optical apparatus according to  claim 1 ; and   developing the photosensitive substrate.   
     
     
         3 . An illumination optical apparatus for illuminating a surface to be illuminated, based on illumination radiation supplied from a radiation source, the illumination optical apparatus comprising:
 a polarization modulating element, which is arranged in an optical path of the illumination radiation, which is made of an optical material with optical activity, and which has a circumferentially varying thickness; and   an optical integrator arranged in an optical path between the polarization modulating element and the surface to be illuminated,   wherein the polarization modulating element has a plurality of circumferentially separated regions, wherein thicknesses of two arbitrary regions adjacent to each other among the plurality of regions are different from each other.   
     
     
         4 . An exposure apparatus comprising the illumination optical apparatus according to  claim 3 ,
 wherein a predetermined pattern is projected onto a photosensitive substrate through the illumination optical apparatus.   
     
     
         5 . A device manufacturing method comprising the steps of:
 projecting a predetermined pattern onto a photosensitive substrate, using the illumination optical apparatus according to  claim 3 ; and   developing the photosensitive substrate.   
     
     
         6 . An illumination optical apparatus for illuminating a surface to be illuminated, based on illumination radiation supplied from a radiation source, the illumination optical apparatus comprising:
 a polarization modulating element, which is arranged in an optical path of the illumination radiation, which is made of an optical material with optical activity, and which has a circumferentially varying thickness; and   a polarization monitor arranged in a downstream optical path of the polarization modulating element, which detects the illumination radiation.   
     
     
         7 . A device manufacturing method comprising the steps of:
 projecting a predetermined pattern onto a photosensitive substrate, using the illumination optical apparatus according to  claim 6 ; and   developing the photosensitive substrate.   
     
     
         8 . A polarization-modulating element for modulating a polarization state of incident light into a predetermined polarization state, the polarization-modulating element comprising:
 a circumferentially varying thickness profile, and a central region with no substantial optical activity,   wherein the polarization-modulating element is made of an optical material with optical activity, and   wherein a radial size of the central region is not less than 3/10 of a radial size of an effective region of the polarization-modulating element.   
     
     
         9 . An illumination optical apparatus for illuminating a surface to be illuminated, based on illumination radiation supplied from a radiation source, the illumination optical apparatus comprising:
 the polarization-modulating element according to  claim 8  arranged in an optical path of the illumination radiation   
     
     
         10 . An exposure apparatus comprising the illumination optical apparatus according to  claim 9 ,
 wherein a predetermined pattern is projected onto a photosensitive substrate through the illumination optical apparatus.   
     
     
         11 . A device manufacturing method comprising the steps of:
 projecting a predetermined pattern onto a photosensitive substrate, using the illumination optical apparatus according to  claim 9 ; and   developing the photosensitive substrate.