Patent ID: 8510684

Claim:
A method of correcting a photomask layout to compensate for a three-dimensional (3D) mask effect, the method comprising: receiving by a computer a layout of a mask pattern; obtaining one or more image parameters of a two-dimensional (2D) mask for the layout from a computer simulation; obtaining one or more image parameters of a 3D mask for the layout from a computer simulation; obtaining differences between the one or more image parameters of the 2D and 3D masks; compensating for the differences between the one or more image parameters of the 2D and 3D masks by convolving a probability function with respect to an open area, represented by a visible kernel function, Ψ op , with a mask function M(x,y), to produce a first function, convolving a probability function with respect to a blocked area, represented by a visible kernel function, Ψ bl , with the mask function M(x,y) to produce a second function, and summing the first function and the second function to produce a compensated vector {right arrow over (Comp)}, as expressed by {right arrow over (Comp)}= C op ·Ψ op ( x,y ) M ( x,y )+ C bl ·Ψ bl ( x,y ) M ( x,y )+ C 0 , wherein C op , C bl , and C 0 are constants determined to minimize an error between the compensated vector {right arrow over (Comp)} and differences {right arrow over (diff)} between the image parameters of the 2D and the image parameters of the 3D masks; and correcting the photomask layout by modeling optical proximity correction (OPC) with the compensated vector {right arrow over (Comp)}.