Projection optical system adjustment method, prediction method, evaluation method, adjustment method, exposure method and exposure apparatus, program, and device manufacturing method

Abstract

Wavefront aberration of a projection optical system is measured and information on the wavefront aberration is obtained (step 102 ). Furthermore, a pattern of a reticle is transferred onto a wafer via a projection optical system (steps 104 to 108 ). Then, the waver on which the pattern is transferred is developed, and line width measurement is performed on the resist image formed on the wafer and line width difference of images of a first line pattern extending in a predetermined direction and a second line pattern that is orthogonal to the first line pattern is measured (steps 112 to 118 ). And, according to a value of the 12 th term of the Zernike polynomial, which is an expansion of the wavefront aberration, and the line width difference, the projection optical system is adjusted so that magnitude of the 9 th term (a low order spherical aberration term) is controlled (steps 120 to 124 ).

1 . An adjustment method of a projection optical system that projects an image of a pattern on a first surface onto a second surface, said method comprising; 
 obtaining information on wavefront aberration of said projection optical system;    obtaining information on a projected image of said pattern; and    adjusting said projection optical system, among a plurality of Zernike terms that are a series expansion of said wavefront aberration using the Zernike polynomial, taking into consideration the Zernike sensitivity of a certain Zernike term combination cross-term whose interaction affects said characteristics of said projected image with respect to a change in characteristics of said projected image.    
   
   
       2 . The adjustment method of said projection optical system of  claim 1  wherein 
 said pattern includes a line pattern, and    said characteristics of said projected image include line width of an image of said line pattern.    
   
   
       3 . An exposure method of transferring a circuit pattern on a first surface onto an object disposed on a second surface via a projection optical system, said method comprising: 
 adjusting said projection optical system, using an adjustment method of a projection optical system of  claim 1;  and    transferring said circuit pattern onto said object, using said projection optical system that has undergone said adjustment.    
   
   
       4 . An exposure apparatus that transfers a pattern formed on a mask onto an object via an exposure optical system, said apparatus comprising: 
 a projection optical system that has been adjusted using an adjustment method of a projection optical system in  claim 1  as said exposure optical system.    
   
   
       5 . A device manufacturing method that comprises a lithographic process wherein 
 in said lithographic process, exposure is performed using the exposure apparatus in  claim 4 .    
   
   
       6 . A making method of an exposure apparatus that transfers a pattern formed on a mask onto an object via a projection optical system, said making method comprising: 
 adjusting said projection optical system, using an adjustment method of a projection optical system according to  claim 1 .    
   
   
       7 . An evaluation method of evaluating characteristics of an image of a pattern via a projection optical system, said method comprising: 
 obtaining information on wavefront aberration of said projection optical system;    obtaining information related to a projected image of said pattern; and    evaluating characteristics of said image of said pattern, among a plurality of Zernike terms that are a series expansion of said wavefront aberration using the Zernike polynomial, taking into consideration the Zernike sensitivity of a certain Zernike term combination cross-term whose interaction affects said characteristics of said projected image with respect to a change in characteristics of said projected image.    
   
   
       8 . The evaluation method of  claim 7  wherein 
 said pattern includes a line pattern, and    characteristics of said projected image include line width of an image of said line pattern.    
   
   
       9 . An adjustment method of adjusting a formed state of an image of a pattern via a projection optical system, said method comprising: 
 evaluating characteristics of an image of a predetermined pattern arranged corresponding to at least one measurement point in an effective field of said projection optical system, using an evaluation method of  claim 7;  and    adjusting said formed state of said image of said predetermined pattern via said projection optical system based on results of said evaluation.    
   
   
       10 . An exposure method of transferring a pattern on a first surface onto an object disposed on a second surface via a projection optical system, said method comprising: 
 adjusting a formed state of an image of said pattern via said projection optical system, using an adjustment method of  claim 9;  and    transferring said pattern onto said object via said projection optical system, in a state where adjustment has been performed on said formed state of said image.    
   
   
       11 . A device manufacturing method that comprises a lithographic process wherein 
 in said lithographic process, exposure is performed using an exposure method of  claim 10.