Patent ID: 7236916

Claim:
A computer-readable medium embodying instructions that when executed by a processor would provide a tool set for simulating a tri-tone attenuated phase-shifting mask including a plurality of structures, a subset of the structures including a transparent region, an opaque region, and an attenuated region, wherein the opaque region and the attenuated region form a rim, the tool set comprising: means for analyzing optical proximity correction for the subset of the structures; means for providing a same rim width in the subset of the structures, wherein the means for providing includes: means for dividing a first edge of the attenuated region into a plurality of first segments; means for dividing a second edge of the opaque region into a plurality of second segments, wherein each second segment corresponds to a certain first segment; and means for determining whether a second segment moves with its corresponding first segment during optical proximity correction; and means for generating a layout consistent with the means for providing.