Patterning semiconductor layers using phase shifting and assist features

Abstract

A photomask and method of patterning a photosensitive layer using a photomask, the photomask including a substrate and a film coupled to substrate. The film is etched with a phase shifted assist feature, a low aspect ratio assist feature or phase shifted low aspect primary features.

1 . A method of patterning a photosensitive layer comprising: 
 providing the photosensitive layer on a substrate; and    exposing the photosensitive layer to a mask comprised of a primary feature and an assist feature located next to the primary feature, the assist feature phase shifted with respect to the primary feature.    
     
     
         2 . The method of  claim 1  wherein exposing includes exposing the photosensitive layer to the mask, the mask further comprising a film patterned to define the phase shift between the primary and assist features.  
     
     
         3 . The method of  claim 1  wherein exposing includes exposing the photosensitive layer to the mask, the mask further comprising a substrate etched to define the phase shift between the primary and assist features.  
     
     
         4 . The method of  claim 1  wherein exposing includes exposing the photosensitive layer to the mask on which the primary feature comprises a low aspect primary feature.  
     
     
         5 . The method of  claim 1  wherein exposing includes exposing the photosensitive layer to the mask on which the assist feature comprises a low aspect assist feature.  
     
     
         6 . A method of patterning a photosensitive layer comprising: 
 providing the photosensitive layer on a substrate; and    exposing the photosensitive layer to a mask comprised of a primary feature and a low aspect assist feature located next to the primary feature.    
     
     
         7 . The method of  claim 6  wherein exposing includes exposing the photosensitive layer to the mask on which the primary feature comprises a low aspect primary feature.  
     
     
         8 . The method of  claim 6  wherein exposing includes exposing the photosensitive layer to the mask on which the assist feature comprises an assist feature with an aspect ratio of less than 2.5.  
     
     
         9 . The method of  claim 6  wherein exposing includes exposing the photosensitive layer to the mask on which the assist feature comprises an assist feature with an aspect ratio of less than 2.0.  
     
     
         10 . A method of patterning a photosensitive layer comprising: 
 providing the photosensitive layer on a substrate; and    exposing the photosensitive layer to a mask comprised of a first low aspect primary feature and a second low aspect primary feature located next to the first low aspect primary feature, the first low aspect primary feature phase shifted with respect to the second low aspect primary feature.    
     
     
         11 . The method of  claim 10  wherein exposing includes exposing the photosensitive layer to the mask on which the first low aspect primary feature is located next to an assist feature, the assist feature phase shifted with respect to the first low aspect primary feature.  
     
     
         12 . The method of  claim 10  wherein exposing includes exposing the photosensitive layer to the mask on which the first low aspect primary feature is located next to a low aspect assist feature, the low aspect assist feature phase shifted with respect to the first low aspect primary feature.