Disclosed is a system for the signal processing of pattern profile information detected by optically or electronically scanning a pattern on an object such as a semiconductor wafer or a mask. The system includes a pattern information detector responsive to the scanning to generate an electric detection...http://www.google.com/patents/US4639604?utm_source=gb-gplus-sharePatent US4639604 - Method and apparatus for detecting an edge position of a pattern and eliminating overlapping pattern signals
