Microlithography projection objective

Abstract

Microlithography projection objectives for imaging into an image plane a pattern arranged in an object plane are described with respect to suppressing false light in such projection objectives.

1 - 53 . (canceled) 
     
     
         54 . A microlithography projection objective for imaging into an image plane a pattern arranged in an object plane, comprising:
 a plurality of optical components that respectively have at least one optically active surface,   wherein:
 a first optical component of the plurality of optical components has a first optically operative surface that, during the operation of the projection objective, has a first surface region not used by an imaging beam path for imaging the pattern into the image plane; 
 the first optically operative surface is assigned a first shield that masks out the first surface region, not used by the imaging beam path, of the first optically operative surface in order to suppress false light; and 
 the first shield is a shielding coating on the first surface region not used by the imaging beam path. 
   
     
     
         55 . The projection objective of  claim 54 , wherein the first shield is reflective for a wavelength of the light used for imaging. 
     
     
         56 . The projection objective of  claim 54 , wherein the first shield is absorbing for a wavelength of the light used for imaging, or the first shield is provided with an absorbing coating. 
     
     
         57 . The projection objective of  claim 56 , wherein the absorbance of the first shield is at least approximately 95%. 
     
     
         58 . The projection objective of  claim 56 , wherein the first shield has photocatalytic properties. 
     
     
         59 . The projection objective of  claim 54 , wherein the first optically operative surface that is assigned the at least one first shield is a near-field surface. 
     
     
         60 . The projection objective of  claim 54 , wherein the first shield is arranged between the object plane and the first optical component of the projection objective, and/or the first shield is arranged between the last optical component of the projection objective and the image plane. 
     
     
         61 . The projection objective of  claim 54 , wherein the first optical component is a mirror. 
     
     
         62 . The projection objective of  claim 54 , wherein the first optical component is a lens. 
     
     
         63 . The projection objective of  claim 54 , wherein the plurality of optical components comprises a second optical component that has second optically operative surface that, during operation of the projection objective, has a second surface region not used by the imaging beam path for imaging the pattern into the image plane, and the second optically operative surface is assigned a second shield that masks out the second surface region, not used by the imaging beam path, of the second optically operative surface. 
     
     
         64 . The projection objective of  claim 54 , wherein the plurality of optical components comprises at least two mirrors. 
     
     
         65 . The projection objective of  claim 64 , wherein the plurality of optical components comprises at least four mirrors. 
     
     
         66 . The projection objective of  claim 54 , wherein the projection objective is an immersion projection objective. 
     
     
         67 . The projection objective of  claim 54 , further comprising at least a further shield configured to shield over-aperture light from the object plane. 
     
     
         68 . The projection objective of  claim 55 , wherein the first shield is absorbing for a wavelength of the light used for imaging, or the first shield is provided with an absorbing coating. 
     
     
         69 . The projection objective of  claim 57 , wherein the first shield has photocatalytic properties. 
     
     
         70 . The projection objective of  claim 55 , wherein the first optically operative surface that is assigned the at least one first shield is a near-field surface. 
     
     
         71 . The projection objective of  claim 55 , wherein the first shield is arranged between the object plane and the first optical component of the projection objective, and/or the first shield is between the last optical component of the projection objective and the image plane. 
     
     
         72 . The projection objective of  claim 55 , wherein the first optical component is a mirror. 
     
     
         73 . A microlithography projection exposure machine, comprising a projection objective as claimed in  claim 54 .