Method of modeling a mask by taking into account of mask pattern edge interaction

Abstract

A mask layout is received. An interaction-free mask model is applied to the mask layout. An edge interaction model is applied to the mask layout. The edge interaction model describes an influence due to a plurality of combinations of two or more edges interacting with one another. A thin mask model is applied to the mask layout. A near field is determined based on the applying of the interaction-free mask model, the applying of the edge interaction model, and the applying of the thin mask model.

What is claimed is: 
     
         1 . A method, comprising:
 accessing a tile that contains a first pattern, a second pattern, a first pixel located on an edge of the first pattern, a second pixel located on an edge of the second pattern, and a third pixel that is outside of the first pattern and the second pattern;   determining an influence exerted to the third pixel by the first pixel and the second pixel;   generating, based at least in part on the influence exerted to the third pixel by the first pixel and the second pixel, an edge interaction kernel for the third pixel; and   determining, based at least in part on the edge interaction kernel, a near field correction at the third pixel.   
     
     
         2 . The method of  claim 1 , wherein the first pixel and the second pixel are located within a predefined proximity of one another. 
     
     
         3 . The method of  claim 1 , wherein at least the first pattern or the second pattern is a non-Manhattan pattern. 
     
     
         4 . The method of  claim 1 , further comprising, before the accessing of the tile:
 identifying the first pixel at least in part by taking a gradient of the first pattern; or   identifying the second pixel at least in part by taking a gradient of the second pattern.   
     
     
         5 . The method of  claim 1 , wherein the edge interaction kernel is generated to include a plurality of multi-dimensional vectors. 
     
     
         6 . The method of  claim 1 , wherein:
 the tile further contains a fourth pixel that is located on a further of the first pattern or the second pattern;   the determining the influence comprises determining the influence exerted to the third pixel by the first pixel, the second pixel, and the fourth pixel; and   the generating the edge interaction kernel is based on the influence exerted to the third pixel by the first pixel, the second pixel, and the fourth pixel.   
     
     
         7 . The method of  claim 1 , wherein:
 the edge interaction kernel is a first edge interaction kernel;   the tile further contains a plurality of additional first pixels that are respectively located on a plurality of additional edges of the first pattern, and a plurality of additional second pixels that are respectively located on a plurality of additional edges of the second pattern; and   the method further comprises: based on the additional pixels and the additional second pixels, repeating the determining the influence and the generating the edge interaction kernel, thereby generating a plurality of additional edge interaction kernels for the third pixel.   
     
     
         8 . The method of  claim 7 , wherein: determining the near field correction comprises performing an integral or a summation based on the first edge interaction kernel and the plurality of additional edge interaction kernels. 
     
     
         9 . The method of  claim 1 , wherein:
 the tile further contains a plurality of additional pixels;   the determining the influence comprises determining the influence exerted to each of the additional pixels by the first pixel and the second pixel;   the generating comprises generating, based on the influence exerted to each of the additional pixels by the first pixel and the second pixel, a plurality of additional edge interaction kernels corresponding to the additional pixels, respectively; and   the determining the near field correction comprises determining the near field correction for each of the additional pixels based on the additional edge interaction kernel corresponding to the respective additional pixel.   
     
     
         10 . The method of  claim 1 , further comprising: before the determining the influence, dividing the tile into a plurality of sub-tiles, and wherein the determining the influence, the generating the edge interaction kernel, and the determining the near field correction are performed based on the plurality of sub-tiles. 
     
     
         11 . The method of  claim 10 , further comprising: surrounding each of the sub-tiles with a respective margin of interaction. 
     
     
         12 . The method of  claim 11 , wherein the generating the edge interaction kernel comprises discarding contributions made by the margin of interaction to the edge interaction kernel. 
     
     
         13 . A method, comprising:
 accessing a tile that contains a plurality of patterns;   identifying edge pixels of the plurality of patterns;   determining an influence exerted to an influenced pixel by the plurality of edge pixels, wherein the influenced pixel is different from any of the edge pixels;   generating, based at least in part on the influence exerted to the influenced pixel by the plurality of edge pixels, an edge interaction kernel for the influenced pixel; and   determining, based at least in part on the edge interaction kernel, a near field correction at the influenced pixel.   
     
     
         14 . The method of  claim 13 , wherein at least some of the patterns are non-Manhattan patterns. 
     
     
         15 . The method of  claim 13 , wherein the tile contains a plurality of further influenced pixels, and wherein the determining the influence exerted and the generating the edge interaction kernel are repeated for each of the further influenced pixels, such that a plurality of further edge interaction kernels are generated, and wherein the near field correction is further based on the plurality of further edge interaction kernels. 
     
     
         16 . The method of  claim 13 , further comprising: dividing the tile into a plurality of sub-tiles, wherein the determining the influence exerted and the generating the edge interaction kernel are performed for each of the sub-tiles. 
     
     
         17 . The method of  claim 16 , wherein:
 a margin of interaction is applied to each of the sub-tiles;   the edge interaction kernel for each of the sub-tiles includes a contribution made by the margin of interaction; and   the near filed correction is determined by removing the contribution made by the margin of interaction.   
     
     
         18 . A method, comprising:
 accessing a portion of a mask layout, wherein the portion of the mask layout includes a plurality of patterns, a plurality of edge pixels located on edges of the patterns, and a plurality of influenced pixels;   determining, for each of the influenced pixels, an influence exerted by the plurality of edge pixels;   generating, based at least in part on the influence exerted to each of the influenced pixels by the plurality of edge pixels, a plurality of edge interaction kernels corresponding to the plurality of influenced pixels, respectively; and   determining, based at least in part on the plurality of edge interaction kernels, a near field correction associated with the portion of the mask layout.   
     
     
         19 . The method of  claim 18 , further comprising: identifying the edge pixels at least in part by taking a gradient of each of the plurality of patterns. 
     
     
         20 . The method of  claim 18 , wherein each of the edge interaction kernels is generated as a function of a plurality of vectors.