Patent ID: 8458628
Filing Date: 2013-06-04
Classification: G03F,G06F

Abstract:
1. A method, comprising: selecting a mask design shape; selecting a region of said mask design shape; using a computer, applying a first optical proximity correction to all regions of said mask design shape, said first optical proximity correction being a model based optical proximity correction based on a computer model of a photolithographic process that generates a simulated photoresist pattern based on said mask design shape; after said applying said first optical proximity correction, using a computer, applying a second optical proximity correction to said selected region of said mask design shape, said second optical proximity correction being a rule based optical proximity correction based on testing for a particular condition occurring in a mask design shape and applying a rule to said mask design shape to change the mask design shape; wherein said mask design shape defines a circuit shape and said selected region of said mask design shape defines a region of said circuit shape that crosses an interface between a first region and a second region of an integrated circuit; and wherein said applying said second optical proximity correction includes placing a design collar on said mask design shape in said selected region, said design collar increasing a width of said mask design shape proximate to said interface in a direction parallel to a reference line corresponding in location and direction to said interface, said design collar extending proximate to said reference line perpendicularly on either side of said reference line.