Projection optical system and method

Abstract

A refractive projection optical system for imaging a first object into a region of a second object comprises a plurality of lenses disposed along an imaging beam path of the projection optical system; wherein the projection optical system is configured to have a numerical aperture on a side of the second object of greater than 1 wherein the projection optical system is configured to generate an intermediate image of the first object and to image the intermediate image into the region of the second object, wherein the intermediate image is formed in between the first and second objects.

1 - 30 . (canceled)  
   
   
       31 . A projection optical system used for an exposure apparatus to projecting a reduced size of an image of an object onto an image plane, said projection optical system comprising plural refractive elements that dispense with a reflective element having a substantial optical power, wherein said projection optical system forms an intermediate image.  
   
   
       32 . The projection optical system according to  claim 31 , wherein only the plural refractive elements have optical powers in said projection optical system.  
   
   
       33 . The projection optical system according to  claim 31 , wherein said projection optical system has a numerical aperture of 1.1 or greater.  
   
   
       34 . The projection optical system according to  claim 31 , wherein a maximum effective diameter of said projection optical system divided by an overall length of said projection optical system is equal to or smaller than 0.20.  
   
   
       35 . The projection optical system according to  claim 31 , wherein a maximum effective diameter of said projection optical system divided by an overall length of said projection optical system is equal to or smaller than 0.25.  
   
   
       36 . The projection optical system according to  claim 31 , wherein −1.50≦β 1 ≦−0.50, where β 1  is a magnification of a first imaging system for forming an intermediate image in said projection optical system.  
   
   
       37 . The projection optical system according to  claim 31 , wherein −1.50≦β 1 ≦−0.40, where β 1  is a magnification of a first imaging system for forming an intermediate image in said projection optical system.  
   
   
       38 . The projection optical system according to  claim 31 , wherein said projection optical system is substantially telecentric both at object side and image side.  
   
   
       39 . The projection optical system according to  claim 31 , wherein a distance between the image plane and an optical surface of said projection optical system closest to the image plane is 20 mm or smaller.  
   
   
       40 . The projection optical system according to  claim 31 , wherein said projection optical system includes, in order from an object side to an image side, first, second, third and fourth units having optically positive powers, a first pupil being formed between the first and second units, the intermediate image being formed between the second and third units, and a second pupil being formed between the third and fourth units.  
   
   
       41 . The projection optical system according to  claim 31 , wherein said projection optical system includes, in order from an object side to an image side, first, second, third and fourth units, at least three units having optically positive powers, a first pupil being formed between the first and second units, the intermediate image being formed between the second and third units, and a second pupil being formed between the third and fourth units.  
   
   
       42 . The projection optical system according to  claim 31 , wherein said projection optical system includes, in order from an object side to an image side, first, second, third and fourth units, the first, second and fourth units having optically positive powers, a first pupil being formed between the first and second units, the intermediate image being formed between the second and third units, and a second pupil being formed between the third and fourth units.  
   
   
       43 . The projection optical system according to  claim 42 , wherein said projection optical system consists of the first, second, third and fourth units.  
   
   
       44 . The projection optical system according to  claim 42 , wherein at least three of the first, second, third and fourth units include a negative lens.  
   
   
       45 . The projection optical system according to  claim 42 , wherein each of the first, second, and third units includes a negative lens.  
   
   
       46 . The projection optical system according to  claim 42 , wherein f 1 ≧f 4 , and f 3 ≧f 4  are met, where f 1  denotes a focal length of the first unit, f 2  denotes a focal length of the second unit, f 3  denotes a focal length of the third unit, and f 4  denotes a focal length of the fourth unit.  
   
   
       47 . The projection optical system according to  claim 42 , wherein 0.078≦f 1 ≦0.15, 0.055≦f 2 /L≦1.917, 0.084≦f 3 /L≦0.276, 0.056≦f 4 /L≦0.066 are met, where f 1  denotes an absolute value of a focal length of the first unit, f 2  denotes an absolute value of a focal length of the second unit, f 3  denotes an absolute value of a focal length of the third unit, and f 4  denotes an absolute value of a focal length of the fourth unit.  
   
   
       48 . An exposure apparatus comprising: 
 an illumination optical system for illuminating an original from light from a light source; and    a projection optical system according to  claim 31  for projecting a pattern of the original onto an object to be exposed.    
   
   
       49 . A device manufacturing method comprising the steps of: 
 exposing an object using an exposure apparatus according to  claim 48;  and    developing the object that has been exposed.