Reduced pitch multiple exposure process

Abstract

A lithographic method to enhance image resolution in a lithographic cluster using multiple projections and a lithographic cluster used to project multiple patterns to form images that are combined to form an image having enhanced resolution.

1 .- 70 . (canceled) 
     
     
         71 . A non-transitory computer readable medium comprising program code that, when executed on a computer system, instructs the computer system to perform a method, the method comprising:
 projecting a first pattern onto an area of a substrate coated with a developable material layer and a first resist layer on top of the developable material layer; and   projecting a second pattern onto an area of the substrate coated with the developable material layer and a second resist layer, wherein no etching of material of or on the substrate immediately beneath the first resist layer and the developable material layer occurs between projecting the first pattern and projecting the second pattern,   wherein projecting the first pattern and projecting the second pattern produces a desired patterned image on the developable material layer.   
     
     
         72 . The computer readable medium of  claim 71 , wherein the desired patterned image comprises patterned features with a half-pitch corresponding to a k1 less than or equal to 0.25. 
     
     
         73 . The computer readable medium of  claim 71 , wherein the method further comprises coating the second resist layer on top of the developable material layer. 
     
     
         74 . The computer readable medium of  claim 73 , wherein the method further comprises:
 after projecting the first pattern and before coating the second resist layer, applying a post exposure bake to the substrate having the first pattern on the first resist layer and the developable material layer.   
     
     
         75 . The computer readable medium of  claim 71 , wherein the method further comprises:
 developing the first resist layer and the developable material layer to form an image of the first pattern on the developable material layer; and   removing the first resist layer.   
     
     
         76 . The computer readable medium of  claim 75 , wherein removing the first resist layer and coating the second resist layer are performed in a same area of a lithographic cluster. 
     
     
         77 . The computer readable medium of  claim 71 , wherein the method further comprises:
 after projecting the second pattern, applying a post exposure bake to the substrate having the second pattern on the second resist layer and the developable material layer;   developing the second resist layer and the developable material layer to form an image of the second pattern in the developable material layer; and   removing the second resist layer.   
     
     
         78 . The computer readable medium of  claim 71 , wherein the method further comprises:
 prior to projecting the second pattern, shifting the substrate in the lithographic cluster by a predetermined distance so as to interleave an image of the second pattern with an image of the first pattern.   
     
     
         79 . A computer readable medium comprising program code that, when executed on a computer system, instructs the computer system to perform a method, the method comprising:
 projecting a first pattern onto an area of a substrate coated with a developable material layer and a resist layer on top of the developable material layer;   applying a first post exposure bake to the substrate having the first pattern in the resist layer and the developable material layer;   projecting a second pattern onto an area of the substrate coated with the developable material layer and the resist layer, wherein material of or on the substrate immediately beneath the resist layer and the developable material layer is not etched between projecting the first pattern and projecting the second pattern; and   applying a second post exposure bake to the substrate having the second pattern in the resist layer and the developable material layer,   wherein projecting the first pattern and the second pattern and applying the first post exposure bake and the second post exposure bake produces a desired image in or on the developable material layer.   
     
     
         80 . The computer readable medium of  claim 79 , wherein the desired image comprises patterned features with a half-pitch corresponding to a k1 less than or equal to 0.25. 
     
     
         81 . The computer readable medium of  claim 79 , wherein a period between features of the first pattern and a period between features of the second pattern is substantially the same. 
     
     
         82 . The computer readable medium of  claim 79 , wherein the method further comprises, before projecting the second pattern, developing the resist layer and the developable material layer to form an image of the first pattern in the developable material layer. 
     
     
         83 . The computer readable medium of  claim 79 , wherein the method further comprises, after applying the second post exposure bake, developing the resist layer and the developable material layer to form an image of the second pattern in the developable material layer. 
     
     
         84 . The computer readable medium of  claim 83 , wherein the method further comprises, after developing the resist layer and the developable material layer to form an image of the second pattern in the developable material layer, removing the resist layer. 
     
     
         85 . The computer readable medium of  claim 79 , wherein the resist layer and developable material layer are not developed between projecting the first pattern and projecting the second pattern. 
     
     
         86 . A computer readable medium comprising program code that, when executed on a computer system, instructs the computer system to perform a method, the method comprising:
 projecting a first pattern onto an area of a substrate coated with a developable material layer and a resist layer on top of the developable material layer;   applying a post exposure bake to the substrate having the first pattern in the resist layer and the developable material layer;   projecting a second pattern onto an area of the substrate coated with the developable material layer and the resist layer, wherein material of or on the substrate immediately beneath the resist layer and the developable material layer is not etched between projecting the first pattern and projecting the second pattern and wherein the resist layer and developable material layer are not developed between projecting the first pattern and projecting the second pattern,   wherein projecting the first pattern and the second pattern and applying the first post exposure bake and the second post exposure bake produces a desired image in or on the developable material layer.   
     
     
         87 . The computer readable medium of  claim 86 , wherein the method further comprises applying a post exposure bake to the substrate having the second pattern in the resist layer and the developable material layer. 
     
     
         88 . The computer readable medium of  claim 86 , wherein the desired image comprises patterned features with a half-pitch corresponding to a k1 less than or equal to 0.25. 
     
     
         89 . The computer readable medium of  claim 86 , wherein the method further comprises, after projecting the second pattern, developing the resist layer and the developable material layer to form an image of the first and second patterns in the developable material layer. 
     
     
         90 . The computer readable medium of  claim 86 , wherein a period between features of the first pattern and a period between features of the second pattern is substantially the same.