Lithographic projection objective

Abstract

Projection objectives, such as projection objectives of lithography projection exposure apparatuses, as well as related systems, components and methods, such as methods of revising and/or repairing such objectives, are disclosed.

1 . (canceled) 
     
     
         2 . A method of modifying a catadioptric lithography projection objective, the catadioptric lithography projection objective comprising a plurality of optical elements between an object plane and an image plane of the catadioptric lithography projection objective, the plurality of optical elements comprising a first optical element arranged at a first location in the catadioptric lithography projection objective, the method comprising:
 removing the first optical element from the catadioptric lithography projection objective in the field at a location of a customer; and   inserting a first spare optical element into the projection objective at the first location;   wherein:
 a surface of the first spare optical element has a shape selected from the group consisting of aspherical and even non-rotational symmetric; 
 the first optical element is a lens element closest to the image plane; and 
 the catadioptric lithography projection objective is selected from the group consisting of an immersion type projection objective and a double immersion type projection objective. 
   
     
     
         3 . The method of  claim 2 , further comprising, prior to inserting the first spare optical element into the catadioptric lithography projection objective, machining the surface of the first spare optical element to provide the surface with the shape that is selected from the group consisting of aspherical and even non-rotational symmetric. 
     
     
         4 . The method of  claim 2 , wherein the first spare optical element is thinner than the first optical element. 
     
     
         5 . The method of  claim 2 , further comprising, after inserting the first spare optical element into the catadioptric lithography projection objective, adjusting an image quality of the catadioptric lithography projection objective to a desired image quality. 
     
     
         6 . The method of  claim 5 , wherein:
 the plurality of optical elements comprises a further optical element; and   adjusting the image quality comprises at least one member selected from the group consisting of moving the further optical element of the plurality of optical elements, deforming the further optical element of the plurality of optical elements, and changing an index distribution of the further optical element.   
     
     
         7 . The method of  claim 5 , wherein adjusting the image quality comprises substantially maintaining an image quality prior to a degradation of the catadioptric lithography projection objective. 
     
     
         8 . The method of  claim 5 , wherein adjusting the image quality comprises altering the image quality compared to an image quality prior to a degradation of the optical system. 
     
     
         9 . The method of  claim 8 , wherein adjusting the image quality comprises increasing a specific image defect in accordance with at least member selected from the group consisting of an illumination setting of the catadioptric lithography projection exposure apparatus and an object to be imaged by the catadioptric lithography projection objective during use of the catadioptric lithography projection objective. 
     
     
         10 . The method of  claim 8 , wherein adjusting the image quality comprises decreasing a specific image defect in accordance with at least member selected from the group consisting of an illumination setting of the catadioptric lithography projection exposure apparatus and an object to be imaged by the catadioptric lithography projection objective during use of the catadioptric lithography projection objective. 
     
     
         11 . The method of  claim 2 , wherein the first optical element has refractive power. 
     
     
         12 . The method of  claim 2 , wherein the first optical element is a plane-parallel plate. 
     
     
         13 . The method of  claim 2 , wherein:
 the plurality of optical elements comprises a second optical element at a second location different from the first location; and   the method further comprises removing the second optical element from the catadioptric lithography projection objective, and inserting a second spare optical element into the catadioptric lithography projection objective at the second location.   
     
     
         14 . The method of  claim 13 , wherein the second spare optical element is designed depending on a difference between: i) an actual image quality of the catadioptric lithography projection objective obtained by a measurement after inserting the first spare optical element; and ii) a desired image quality of the catadioptric lithography projection objective. 
     
     
         15 . The method of  claim 14 , further comprising, prior to inserting the second spare optical element into the catadioptric lithography projection objective, working the second spare optical element. 
     
     
         16 . The method of  claim 15 , wherein working the second spare optical element comprises altering a material thickness of the second spare optical element. 
     
     
         17 . The method of  claim 15 , wherein working the second spare optical element comprises providing a surface of the second spare optical element with a surface selected from the group consisting of aspherical and even non-rotational symmetric. 
     
     
         18 . The method of  claim 14 , wherein the second optical element has refractive power. 
     
     
         19 . The method of  claim 14 , wherein the second optical element is a plane-parallel plate. 
     
     
         20 . A method of modifying a catadioptric lithography projection objective, the catadioptric lithography projection objective comprising a plurality of optical elements between an object plane and an image plane of the catadioptric lithography projection objective, the plurality of optical elements comprising a first optical element arranged at a first location in the catadioptric lithography projection objective, the method comprising:
 removing the first optical element from the catadioptric lithography projection objective in the field at a location of a customer; and   inserting a first spare optical element into the catadioptric lithography projection objective at the first location,   wherein:
 the first spare optical element is thinner than first optical element; 
 the first optical element is a lens element closest to the image plane; and 
 the catadioptric lithography projection objective is selected from the group consisting of an immersion type and a double immersion type. 
   
     
     
         21 . The method of  claim 20 , wherein:
 the plurality of optical elements comprises a second optical element at a second location different from the first location; and   the method further comprises removing the second optical element from the catadioptric lithography projection objective, and inserting a second spare optical element into the catadioptric lithography projection objective at the second location.