Patent ID: 7073162

Claim:
A method of preparing a file that defines one or more objects to be created photolithographically for correction with an optical and process control (OPC) tool, comprising: receiving the file that defines the one or more objects to be created, each object being defined as a polygon in the file; fragmenting each polygon into a number of edge segments that extend around the perimeter of the polygon; defining a control site for at least some of the edge segments; applying a smoothing filter to one or more of the fragmented polygons, the smoothing filter simulating how objects would be created on a wafer from the one or more fragmented polygons; calculating an error for the control sites in the one or more fragmented polygons; and using the calculated errors to adjust the position and/or orientation of the control sites or to eliminate control sites from a polygon prior to applying the OPC tool to the polygons.