Patent ID: 7460962
Filing Date: 2008-12-02
Classification: G03F

Abstract:
1. A method for an optical measuring of an OPC (Optical Proximity Correction) structure associated with a predetermined structure on a photomask, comprising: (a) specifying an area on the photomask including the OPC structure to be measured and a first edge of the predetermined structure; (b) sampling of an intensity image of the specified area row-wise in a first direction perpendicular to the first edge of the predetermined structure, and for each row: (c) based on the locations specified in step (b.1), determining a location lying farthest out with reference to the predetermined structure, and a location lying farthest in with reference to the predetermined structure; and (d) determining a maximum distance between the first edge of the predetermined structure and a first edge of the associated OPC structure based on the difference of the location lying farthest out and the location lying farthest in.