Method of adjusting projection optical apparatus

Abstract

This invention relates to an adjusting method for correcting the random component of distortion of a projection optical apparatus without performing complicated assembly and adjustment. This adjusting method has the first step of measuring the residual distortion component of a projection optical system having a predetermined target member in its optical path, the second step of calculating, based on the measurement result of the first step, the surface shape of the target member to cancel the residual distortion component, the third step of removing the target member from the projection optical system and machining the target member so as to have the surface shape calculated in the second step, and the fourth step of inserting the target member machined in the third step into the optical path of the projection optical system.

What is claimed is:  
     
         1 . A method of adjusting a projection optical apparatus that projects an image of an object which is arranged in a first surface onto a second surface, comprising: 
 a first step of measuring an aberration of the projection optical apparatus having a plurality of optical elements and at least one correction element;    a second step of calculating, based on a measurement result of the first step, a surface shape that the correction element should have, the aberration of the projection optical apparatus being a predetermined value when the correction element has the surface shape that the correction element should have;    a third step of removing the correction element from the projection optical apparatus and machining the correction element so that the surface shape of the correction element coincides with the surface shape calculated in the second step; and    a fourth step of returning the correction element machined in the third step into the projection optical apparatus.    
     
     
         2 . A method according to  claim 1 , further comprising a fifth step of correcting components of various aberrations of the projection optical apparatus that are symmetric with respect to an optical axis of the projection optical apparatus.  
     
     
         3 . A method according to  claim 1 , further comprising a fifth step of measuring components of various aberrations of the projection optical apparatus that are symmetric with respect to an optical axis of the projection optical apparatus.  
     
     
         4 . A method according to  claim 3 , further comprising a sixth step of correcting the components of various aberrations of the projection optical apparatus that are symmetric with respect to the optical axis of the projection optical apparatus.  
     
     
         5 . A method according to  claim 3 , wherein the fifth step is executed prior to the first step.  
     
     
         6 . A method according to  claim 3 , wherein the aberration measured in the first step includes a random component.  
     
     
         7 . A method according to  claim 1 , wherein the correction element is arranged at a most first surface side of the projection optical apparatus.  
     
     
         8 . A method according to  claim 7 , wherein the correction element is a plane-parallel plate.  
     
     
         9 . A method according to  claim 1 , wherein the correction element arranged in the first step is a dummy element and is different from the correction element machined in the third step.  
     
     
         10 . A method according to  claim 1 , wherein the correction element in the first step has a predetermined refracting power.  
     
     
         11 . A method of manufacturing a projection optical apparatus comprising the steps of: 
 preparing the projection optical apparatus; and    adjusting the projection optical apparatus by a method according to  claim 1 .    
     
     
         12 . A projection optical apparatus manufactured by a method according to  claim 11 .  
     
     
         13 . An exposure apparatus comprising: 
 an illumination apparatus;    the projection optical apparatus adjusted in accordance with a method according to  claim 1;     a first stage, arranged between the illumination apparatus and the projection optical apparatus, for holding a mask on a position of the first surface; and    a second stage for holding a photosensitive substrate on a position of the second surface.    
     
     
         14 . A method of manufacturing a circuit pattern, using an exposure apparatus according to  claim 13 , the method comprising the step of printing the circuit pattern on the mask onto the photosensitive substrate.  
     
     
         15 . A method of adjusting a projection optical apparatus that projects an image of an object which is arranged in a first surface onto a second surface, comprising: 
 a first step of measuring an aberration of the projection optical apparatus having a plurality of optical elements and at least one correction element; and    a second step of correcting, based on a measurement result of the first step, the aberration of the projection optical apparatus to a predetermined value;    wherein the second step comprises a first sub-step of obtaining a correction shape with respect to an optical surface of the correction element, a second sub-step of machining the optical surface so that the optical surface has the correction shape, a third sub-step of coating a film on the optical surface, and a fourth sub-step of placing the optical surface at an optical path of the projection optical system.    
     
     
         16 . A method according to  claim 15 , wherein the film on the optical surface includes an anti-reflection film.  
     
     
         17 . A method according to  claim 15 , wherein the correction element in the first step is a dummy element and is different from the correction element machined in the second sub-step.  
     
     
         18 . A method according to  claim 15 , wherein the correction element is a plane-parallel plate.  
     
     
         19 . A method according to  claim 15 , wherein the correction element in the first step has a predetermined refracting power.  
     
     
         20 . A method of manufacturing a projection optical apparatus comprising the steps of: 
 preparing the projection optical apparatus; and    adjusting the projection optical apparatus by a method according to  claim 15 .    
     
     
         21 . A projection optical apparatus manufactured by a method according to  claim 20 .  
     
     
         22 . An exposure apparatus comprising: 
 an illumination apparatus;    the projection optical apparatus adjusted in accordance with a method according to  claim 15;     a first stage, arranged between the illumination apparatus and the projection optical apparatus, for holding a mask on a position of the first surface; and    a second stage for holding a photosensitive substrate on a position of the second surface.    
     
     
         23 . A method of manufacturing a circuit pattern, using an exposure apparatus according to  claim 22 , the method comprising the step of printing the circuit pattern on the mask onto the photosensitive substrate.  
     
     
         24 . A method of adjusting a projection optical apparatus that projects an image of an object which is arranged in a first surface onto a second surface, and that has a plurality of optical elements and at least one correction element, comprising: 
 a first step of adjusting a position of at least one of the optical elements; and    a second step of correcting an aberration of the projection optical apparatus to a predetermined value;    wherein the second step comprises a first sub-step of obtaining a correction shape with respect to an optical surface of the correction element, a second sub-step of machining the optical surface so that the optical surface has the correction shape, and a third sub-step of placing the optical surface at an optical path of the projection optical apparatus.    
     
     
         25 . A method according to  claim 24 , wherein the first step comprises a sub-step of adjusting a distance between the optical elements.  
     
     
         26 . A method according to  claim 25 , wherein the first step comprises a sub-step of adjusting tilt shift of the optical elements.  
     
     
         27 . A method according to  claim 24 , further comprising: 
 a third step of measuring an aberration of the projection optical apparatus having the plurality of optical elements and the correction element;    wherein the correcting the aberration of the projection optical system is performed based on a measurement result of the third step.    
     
     
         28 . A method of manufacturing a projection optical apparatus comprising the steps of: 
 preparing the projection optical apparatus; and    adjusting the projection optical apparatus by a method according to  claim 24 .    
     
     
         29 . A projection optical apparatus manufactured by a method according to  claim 28 .  
     
     
         30 . An exposure apparatus comprising: 
 an illumination apparatus;    the projection optical apparatus adjusted in accordance with a method according to  claim 24;     a first stage, arranged between the illumination apparatus and the projection optical apparatus, for holding a mask on a position of the first surface; and    a second stage for holding a photosensitive substrate on a position of the second surface.    
     
     
         31 . A method of manufacturing a circuit pattern using an exposure apparatus according to  claim 30 , the method comprising the step of printing the circuit pattern on the mask onto the photosensitive substrate.