Patent Document ID: 7831954
Application ID: 11861195
Patent Flag: 1

Claim One:
1. A method for computing the effect of perturbations to an input pattern layout during an OPC (Optical Proximity Correction) process, the method comprising: receiving a pattern layout; receiving a set of lithography model kernels; obtaining a set of convolved patterns by convolving the pattern layout with each of the set of lithography model kernels; computing, using at least a computer, a model flash lookup table for each of the lithography model kernels, wherein the model flash lookup table contains precomputed values for a set of convolution functions obtained by convolving a set of basis functions with the lithography model kernel; applying a perturbation pattern to the pattern layout; for a query location in a plurality of query locations on the pattern layout, obtaining a set of convolution values at the query location by using the model flash lookup tables to convolve the perturbation pattern with the set of lithography model kernels; updating the set of convolved patterns at the query location to account for the effect of the perturbation pattern on the pattern layout by combining the set of convolution values, which represents the effect of the perturbation pattern, with the set of convolved patterns, which are computed from the pattern layout; and computing an intensity value at the query location.