Beam transforming element, illumination optical apparatus, exposure apparatus, and exposure method with two optical elements having different thicknesses

Abstract

A beam transforming element for forming a predetermined light intensity distribution on a predetermined surface on the basis of an incident beam includes a first basic element made of an optical material with optical activity, for forming a first region distribution of the predetermined light intensity distribution on the basis of the incident beam; and a second basic element made of an optical material with optical activity, for forming a second region distribution of the predetermined light intensity distribution on the basis of the incident beam, wherein the first basic element and the second basic element have their respective thicknesses different from each other along a direction of transmission of light.

1 . An apparatus which illuminates a surface to be illuminated with radiation from a radiation source, the apparatus comprising:
 an optical element made of an optical material with optical activity, an optic axis of the optical material of the optical element being aligned along an optical axis of the apparatus.   
   
   
       2 . The apparatus according to  claim 1 , wherein the optical element includes a first basic element and a second basic element. 
   
   
       3 . The apparatus according to  claim 2 , further comprising:
 a diffractive surface arranged in an illumination path of the apparatus which generates a first diffracted radiation and a second diffracted radiation based on the radiation from the radiation source, the first diffracted radiation and the second diffracted radiation reach different regions on an illumination pupil of the apparatus;   the first basic element provides the first diffracted radiation with optical rotation; and   the second basic element provides the second diffracted radiation with optical rotation, and the first and second basic elements have respective thicknesses different from each other along a direction of transmission of light.   
   
   
       4 . The apparatus according to  claim 3 , further comprising an optical integrator arranged between the first and second basic elements and the surface to be illuminated. 
   
   
       5 . The apparatus according to  claim 4 , wherein the diffractive surface is arranged between the first and second basic elements and the surface to be illuminated. 
   
   
       6 . The apparatus according to  claim 3 , wherein the diffractive surface is arranged between the first and second basic elements and the surface to be illuminated. 
   
   
       7 . The apparatus according to  claim 2 , wherein the first and second basic elements are arranged in a plane which is disposed in an illumination path of the apparatus. 
   
   
       8 . The apparatus according to  claim 2 , further comprising:
 a diffractive surface which is arranged in an illumination path of the apparatus, and which forms a first region distribution of the predetermined light intensity distribution and a second region distribution of the predetermined light intensity distribution on the basis of radiation from the radiation source, the first basic element provides a first rotation angle to an incident linearly polarized radiation and has a first thickness along a direction of transmission of radiation, and the linearly polarized radiation from the first basic element propagates to the first region distribution;   the second basis element provides a second rotation angle to an incident linearly polarized radiation and has a second thickness along a direction of transmission of radiation, the second thickness differs from the first thickness, and the linearly polarized radiation from the second basic element propagates to the second region distribution.   
   
   
       9 . The apparatus according to  claim 8 , further comprising an optical integrator arranged between the first and second basic elements and the surface to be illuminated. 
   
   
       10 . The apparatus according to  claim 9 , wherein the diffractive surface is arranged between the first and second basic elements and the surface to be illuminated. 
   
   
       11 . The apparatus according to  claim 8 , wherein the diffractive surface is arranged between the first and second basic elements and the surface to be illuminated. 
   
   
       12 . The apparatus according to  claim 2 , further comprising a diffractive surface arranged in an illumination path of the apparatus which generates a first diffracted radiation and a second diffracted radiation based on the radiation from the radiation source, the first and second diffracted radiations reach different regions on an illumination pupil of the apparatus. 
   
   
       13 . The apparatus according to  claim 12 , wherein the diffractive surface forms an illumination pupil distribution which is formed on or near an illumination pupil of the apparatus. 
   
   
       14 . The apparatus according to  claim 2 , wherein the first basic element and the second basic element are integrally formed. 
   
   
       15 . An exposure apparatus comprising the apparatus as defined in  claim 1 , which illuminates a predetermined pattern and projects the predetermined pattern onto a photosensitive substrate. 
   
   
       16 . The exposure apparatus according to  claim 15 , wherein an illumination pupil distribution on or near an illumination pupil of the apparatus is a distribution in at least a part of a predetermined annular region, which is a predetermined annular region centered around an optical axis of the apparatus. 
   
   
       17 . The exposure apparatus according to  claim 16 , wherein a polarization state of the beam at the illumination pupil is set based on an influence of an optical member disposed in an optical path between the light source and the photosensitive substrate. 
   
   
       18 . The exposure apparatus according to  claim 17 , wherein the optical member including a reflective surface. 
   
   
       19 . The exposure apparatus according to  claim 16 , wherein a polarization state of the beam at the illumination pupil is set so that light illuminating the photosensitive substrate is in a polarization state in which a principal component is s-polarized light. 
   
   
       20 . An exposure method comprising:
 illuminating a predetermined pattern using the exposure apparatus as defined in  claim 15 ; and   projecting an image of the predetermined pattern onto a photosensitive substrate.   
   
   
       21 . A device manufacturing method comprising:
 illuminating a predetermined pattern using the exposure apparatus as defined in  claim 15 ;   projecting an image of the predetermined pattern onto a photosensitive substrate; and   developing the photosensitive substrate.   
   
   
       22 . An exposure method comprising:
 supplying radiation;   passing the radiation through an optical element made of an optical material with optical activity, an optic axis of the optical material of the optical element being aligned along a traveling direction of an incident radiation;   illuminating a pattern with radiation passed through the optical element; and   projecting an image of the pattern using the radiation with which the pattern was illuminated.   
   
   
       23 . The method according to  claim 22 , wherein the optical element includes a first basic element and a second basic element, and radiation is passed through the first and second basic elements. 
   
   
       24 . The method according to  claim 23 , further comprising:
 generating a first diffracted radiation and a second diffracted radiation, the first and second diffracted radiations reach different regions on an illumination pupil;   optically rotating the first diffracted radiation using the first basic element; and   optically rotating the second diffracted radiation using the second basic element, wherein the first and second basics elements have thicknesses different from each other along a direction of transmission of light.   
   
   
       25 . The method according to  claim 24 , further comprising passing the radiations from the first and second basic element through an optical integrator. 
   
   
       26 . The method according to  claim 25 , wherein the first and second diffracted radiations are generated by radiations from the first and second basic elements. 
   
   
       27 . The method according to  claim 24 , wherein the first and second diffracted radiations are generated by radiations from the first and second basic elements. 
   
   
       28 . The method according to  claim 23 , wherein the first and second basic elements are arranged in a plane disposed in an illumination path of the radiation. 
   
   
       29 . A method according to  claim 23 , further comprising:
 generating a first diffracted radiation and a second diffracted radiation, the first and second diffracted radiations reach different regions on an illumination pupil;   propagating the first diffracted radiation to a first region distribution on the illumination pupil;   propagating the second diffracted radiation to a second region distribution on the illumination pupil;   rotating by a first rotation angle an incident linearly polarized radiation using the first basic element having a first thickness along a direction of transmission of the first diffracted radiation; and   rotating by a second rotation angle an incident linearly polarized radiation with the second basic element having a second thickness along the direction of transmission of radiation, wherein the second thickness differs from the first thickness.   
   
   
       30 . The method according to  claim 29 , further comprising passing the radiations from the first and second basic elements through an optical integrator. 
   
   
       31 . The method according to  claim 30 , wherein the first and second diffracted radiations are generated by radiations from the first and second basic elements. 
   
   
       32 . The method according to  claim 29 , wherein the first and second diffracted radiations are generated by radiations from the first and second basic elements. 
   
   
       33 . The method according to  claim 23 , further comprising generating a first diffracted radiation and a second diffracted radiation, the first and second diffracted radiations reach different regions on an illumination pupil of the apparatus. 
   
   
       34 . The method according to  claim 33 , further comprising forming an illumination pupil distribution which is formed on or near an illumination pupil of the apparatus by use of the first and the second diffracted radiations. 
   
   
       35 . The method according to  claim 23 , wherein the first basic element and the second basic element are integrally formed. 
   
   
       36 . A device manufacturing method comprising:
 projecting an image of a pattern onto a photosensitive substrate using the exposure method according to  claim 22 ; and   processing the photosensitive substrate to form the device.