Uniformity correction system having light leak and shadow compensation

Abstract

A system and method for uniformity correction having light leak and shadow compensation is provided. The system includes multiple correction elements and an optical compensation plate. Adjacent correction elements are separated by a gap. The optical compensation plate includes a pattern having multiple gap compensation segments. The pattern has an attenuation which is different than the attenuation of the remaining portions of the optical compensation plate. The location of each compensation segment on the compensation plate corresponds to the location of the corresponding gap between adjacent correction elements in the illumination slot. The width of each compensation segment is dependent upon the angle of the light incident on the correction system. The pattern can be located on the top surface or on the bottom surface of the compensation plate. In addition, the compensation plate can be located above or below the plurality of correction elements.

1 . A lithography apparatus, comprising:
 an illumination system configured to generate a beam of radiation;   a uniformity correction system configured to process the beam of radiation and including:
 a plurality of correction elements, wherein adjacent one of the correction elements are spaced apart, and 
 a plate including a plurality of segments, each of the plurality of segments having an attenuation different than an attenuation of the plate and corresponding to a space between the adjacent correction elements; 
   a patterning device configured to pattern the processed beam; and   a projection system configured to project the patterned beam onto a target area of a substrate.   
   
   
       2 . The lithography apparatus of  claim 1 , wherein the plate is parallel to the plurality of correction elements. 
   
   
       3 . The lithography apparatus of  claim 1 , wherein at least one dimension of a segment in the plurality of segments is determined by the angle of light incident on the uniformity correction system. 
   
   
       4 . The lithography apparatus of  claim 1 , wherein the plate has a first surface and a second surface and wherein the plurality of segments is on the first surface. 
   
   
       5 . The lithography apparatus of  claim 1 , wherein the plate has a first surface and a second surface and wherein the plurality of segments is on the second surface. 
   
   
       6 . The lithography apparatus of  claim 1 , wherein the plurality of segments are included within the body of the plate. 
   
   
       7 . The lithography apparatus of  claim 1 , wherein the plurality of segments have a non-zero attenuation and the plate has a zero attenuation. 
   
   
       8 . A lithography apparatus, comprising:
 an illumination system configured to generate a beam of radiation;   a uniformity correction system configured to control an illumination level within the beam of radiation, including:
 a plurality of correction elements arranged in a tilted configuration, wherein when the plurality of correction elements are inserted to a maximum depth in a correction slot, a plurality of parallel gaps extending substantially across the width of the correction slot are created, and 
 a compensation plate including a plurality of parallel compensation segments extending substantially across the width of the compensation plate, wherein each of the plurality of compensation segments corresponds to one of the plurality of the plurality of parallel gaps; 
   a patterning device configured to pattern the beam of radiation received from the uniformity correction system; and   a projection system configured to project the patterned beam onto a target area of a substrate.   
   
   
       9 . The lithography apparatus of  claim 8 , wherein the plurality of parallel compensation segments has a first attenuation and the compensation plate has a second attenuation. 
   
   
       10 . The lithography apparatus of  claim 8 , wherein the plate is parallel to the plurality of correction elements. 
   
   
       11 . The lithography apparatus of  claim 8 , wherein at least one dimension of a segment in the plurality of parallel segments is determined by the angle of light incident on the uniformity correction system. 
   
   
       12 . The lithography apparatus of  claim 8 , wherein the compensation plate has a first surface and a second surface and wherein the plurality of parallel segments is on the first surface. 
   
   
       13 . The lithography apparatus of  claim 8 , wherein the compensation plate has a first surface and a second surface and wherein the plurality of parallel segments is on the second surface. 
   
   
       14 . The lithography apparatus of  claim 8 , wherein the plurality of parallel segments are included within the body of the compensation plate. 
   
   
       15 . The lithography apparatus of system of  claim 9 , wherein the first attenuation is non-zero attenuation and the second attenuation is zero. 
   
   
       16 . A lithography apparatus, comprising:
 an illumination system configured to generate a beam of radiation;   a uniformity correction system configured to control an illumination level within the beam of radiation, including:
 a plurality of correction members, movable within an illumination slot, wherein each correction member is separated from an adjacent correction member by a gap; and 
 an optical compensation plate, 
 wherein the optical compensation plate includes a pattern having an attenuation, the pattern having a plurality of pattern segments, 
 wherein the arrangement of the pattern on the optical compensation plate corresponds to the arrangement of the gaps between adjacent correction members when each correction member is inserted to a maximum depth in the illumination slot; 
   a patterning device configured to pattern the beam of radiation received from the uniformity correction system; and   a projection system configured to project the patterned beam onto a target area of a substrate.   
   
   
       17 . The lithography apparatus of  claim 16 , wherein the attenuation of the pattern is greater than an attenuation of the optical compensation plate. 
   
   
       18 . The lithography apparatus of  claim 16 , wherein the optical compensation plate is placed beneath the plurality of correction members. 
   
   
       19 . The lithography apparatus of  claim 16 , wherein the optical compensation plate is placed above the plurality of correction members.