Optical proximity correction for free form shapes

One or more non-transitory computer-readable media storing computer-executable instructions for causing one or more processors to perform a method, the method comprising:

• fragmenting boundary lines of layout features in a layout design into straight line fragments, the fragmenting comprising using some of the straight line fragments to represent curved boundary line segments of the layout features;
• and
• generating modified layout features based on a plurality of optical proximity correction iterations, each of the plurality of optical proximity correction iterations comprising:
• computing edge adjustment values for the straight line fragments based on edge placement errors derived from an optical proximity correction iteration immediately preceding the each of the plurality of optical proximity correction iterations,
• adjusting locations of the straight line fragments based on the determined edge adjustment values,
• determining smooth boundary lines for the layout features based on the straight line fragments on the adjusted locations,
• performing a simulation process on the layout features having the smooth boundary lines to determine a simulated image of the layout features, and
• deriving the edge adjustment errors for the straight line fragments based on comparing the simulated image with a target image of the layout features.

A system, comprising:

• one or more processors, the one or more processors programmed to perform a method, the method comprising:
• fragmenting boundary lines of layout features in a layout design into straight line fragments, the fragmenting comprising using some of the straight line fragments to represent curved boundary line segments of the layout features;
• and
• generating modified layout features based on a plurality of optical proximity correction iterations, each of the plurality of optical proximity correction iterations comprising:
• computing edge adjustment values for the straight line fragments based on edge placement errors derived from an optical proximity correction iteration immediately preceding the each of the plurality of optical proximity correction iterations,
• adjusting locations of the straight line fragments based on the determined edge adjustment values,
• determining smooth boundary lines for the layout features based on the straight line fragments on the adjusted locations,
• performing a simulation process on the layout features having the smooth boundary lines to determine a simulated image of the layout features, and
• deriving the edge adjustment errors for the straight line fragments based on comparing the simulated image with a target image of the layout features.