Patent ID: 7260812

Claim:
A method for expediting or stabilizing convergence in a model-based optical proximity correction (OPC) process, comprising: receiving a layout for an integrated circuit; dissecting shapes in the layout into a number of segments; and running a number of OPC iterations on the segments to produce an OPC-corrected layout, wherein each OPC iteration involves: calculating a chrome shift for each segment based on a current layout obtained from the previous iteration, wherein the chrome shift is how far an edge between an opaque region and a transparent region in each segment should be moved, wherein the chrome shift for a segment is measured from the previous position of the chrome edge in that segment, and wherein the chrome shift indicates the difference between the layouts at two consecutive iterations; calculating an adjusted chrome shift for each segment based on the newly calculated chrome shift and chrome shift values obtained in one or more previous iterations, wherein each iteration further involves clamping the adjusted chrome shift for each segment by limiting the maximum absolute value of the chrome shift to a pre-determined value; and applying the adjusted chrome shift values to the current layout to obtain an updated layout.