Microlithography projection optical system and method for manufacturing a device

Abstract

In some embodiments, a catoptric microlithgraphy projection optical system includes a plurality of reflective optical elements arranged to image radiation from an object field in an object plane to an image field in an image plane. The image field can have a size of at least 1 mm×1 mm. This optical system can have an object-image shift (OIS) of about 75 mm or less. Metrology and testing can be easily implemented despite rotations of the optical system about a rotation axis. Such a catoptric microlithgraphy projection optical system can be implemented in a microlithography tool. Such a microlithography tool can be used to produce microstructured components.

1 .- 27 . (canceled) 
     
     
         28 . A system, comprising:
 a plurality of reflective elements configured to image radiation from an object field in an object plane of the system to an image field in an image plane of the system,   wherein:
 the system has an object image shift of about 75 mm or less; 
 the image field is a rectangular field defined by two orthogonal directions; 
 each orthogonal direction has a minimum dimension of about 1 mm or more; 
 the system has an image-side numerical aperture of about 0.2 or more; and 
 the system is a catoptric microlithography projection optical system. 
   
     
     
         29 . The system of  claim 28 , wherein the image-side numerical aperture of the system is more than 0.3. 
     
     
         30 . The system of  claim 28 , wherein:
 a path of the radiation through the system is characterized by chief rays;   for a meridional section of the optical system, a chief ray of a central field point has a maximum angle of incidence on a reflective surface of each of the plurality of reflective elements of θ degrees;   the image side numerical aperture of the optical system is more than 0.3; and   a ratio θ/NA is less than 68.   
     
     
         31 . The system of  claim 28 , wherein at least one of the plurality of reflective elements has a rotationally asymmetric surface positioned in a path of the radiation, and the rotationally asymmetric surface deviates from a best-fit rotationally symmetric surface by at least at one or more locations, where λ is the wavelength of the radiation. 
     
     
         32 . The system of  claim 31 , wherein the best-fit rotationally asymmetric surface deviates by about 0.1λ or less from a surface corresponding to the equation: 
       
         
           
             
               z 
               = 
               
                 
                   
                     cr 
                     2 
                   
                   
                     1 
                     + 
                     
                       
                         1 
                         - 
                         
                           
                             ( 
                             
                               1 
                               + 
                               k 
                             
                             ) 
                           
                            
                           
                             c 
                             2 
                           
                            
                           
                             r 
                             2 
                           
                         
                       
                     
                   
                 
                 + 
                 
                   
                     ∑ 
                     
                       j 
                       = 
                       2 
                     
                     α 
                   
                    
                   
                       
                   
                    
                   
                     
                       C 
                       j 
                     
                      
                     
                       x 
                       m 
                     
                      
                     
                       y 
                       n 
                     
                   
                 
               
             
           
         
         
           
             where 
           
         
         
           
             
               
                 j 
                 = 
                 
                   
                     
                       
                         
                           ( 
                           
                             m 
                             + 
                             n 
                           
                           ) 
                         
                         2 
                       
                       + 
                       m 
                       + 
                       
                         3 
                          
                         n 
                       
                     
                     2 
                   
                   + 
                   1 
                 
               
               , 
             
           
         
         z is the sag of the surface parallel to a Z-axis of a Cartesian co-ordinate system, x and y are co-ordinates along an X-axis and a Y-axis, respectively, of the Cartesian co-ordinate system, r 2 =x 2 +y 2 , m and n are natural numbers, c is the vertex curvature and k is the conical constant, C j  is the coefficient of the monomial x m y n , and α is an integer. 
       
     
     
         33 . The system of  claim 31 , wherein the rotationally asymmetric surface deviates from the best-fit rotationally symmetric surface by about 10λ or more at the one or more locations. 
     
     
         34 . The system of  claim 28 , wherein the plurality of reflective elements define a meridional plane and the plurality of reflective elements are mirror symmetric with respect to the meridional plane. 
     
     
         35 . The system of  claim 28 , wherein the plurality of reflective elements comprises two elements that are reflective elements and that have rotationally asymmetric surfaces positioned in a path of the radiation. 
     
     
         36 . The system of  claim 28 , wherein the plurality of elements includes at most two reflective elements that have a positive chief ray angle magnification. 
     
     
         37 . The system of  claim 28 , wherein the plurality of elements includes at most one reflective element that has a positive chief ray angle magnification. 
     
     
         38 . The system of  claim 28 , wherein wavefront error at the image field is about λ/14 or less, where λ is the wavelength of the radiation. 
     
     
         39 . The system of  claim 28 , wherein chief rays are parallel to each other to within 0.05° at the object plane. 
     
     
         40 . The system of  claim 28 , wherein chief rays diverge from each other at the object plane. 
     
     
         41 . The system of  claim 28  wherein, for a meridional section of the system, chief rays have a maximum angle of incidence on a surface of each of the elements of less than 20°. 
     
     
         42 . The system of  claim 28 , wherein the system is telecentric at the image plane. 
     
     
         43 . The system of  claim 28 , further comprising a radiation source configured to provide the radiation to an object plane, wherein a wavelength of the radiation is about 30 nm or less. 
     
     
         44 . A tool, comprising:
 an illumination system comprising one or more optical elements; and   a catoptric microlithography projection optical system, comprising:
 a plurality of reflective elements configured to image radiation from an object field in an object plane of the catoptric microlithography projection optical system to an image field in an image plane of the catoptric microlithography projection optical system, 
   wherein:
 the catoptric microlithography projection optical system has an object image shift of about 75 mm or less; 
 the image field is a rectangular field defined by two orthogonal directions; 
 each orthogonal direction has a minimum dimension of about 1 mm or more; 
 the catoptric microlithography projection optical system has an image-side numerical aperture of about 0.2 or more; and 
 the tool is a microlithography tool. 
   
     
     
         45 . A method of using a microlithography tool comprising an illumination system and a catoptric projection optical system, the method comprising:
 using the illumination system to illuminate an object in an object field; and   using the catoptric projection optical system to project the object into an image field,   wherein the catoptric projection optical system comprises the system of  claim 28 .   
     
     
         46 . A system, comprising:
 a plurality of reflective elements configured to image radiation from an object field in an object plane of the system to an image field in an image plane of the system,   wherein:
 the system has an object image shift of about 75 mm or less; 
 the image field has a size of at least 1 mm×1 mm; 
 the system has an image-side numerical aperture of about 0.4 or more; and 
 the system is a catoptric microlithography projection optical system. 
   
     
     
         47 . The system of  claim 46 , wherein the image field is a rectangular field defined by two orthogonal directions, and each orthogonal direction has a minimum dimension of about 1 mm or more. 
     
     
         48 . A tool, comprising:
 an illumination system comprising one or more optical elements; and   a catoptric microlithography projection optical system, comprising:
 a plurality of reflective elements configured to image radiation from an object field in an object plane of the catoptric microlithography projection optical system to an image field in an image plane of the catoptric microlithography projection optical system, 
   wherein:
 the catoptric microlithography projection optical system has an object image shift of about 75 mm or less; 
 the image field has a size of at least 1 mm×1 mm; 
 the system has an image-side numerical aperture of about 0.4 or more; and 
 the tool is a microlithography tool. 
   
     
     
         49 . A method of using a microlithography tool comprising an illumination system and a catoptric projection optical system, the method comprising:
 using the illumination system to illuminate an object in an object field; and   using the catoptric projection optical system to project the object into an image field,   wherein the catoptric projection optical system comprises the system of  claim 46 .