抄録
When an inspection process compares a detected circuit pattern with a reference pattern to search for pattern defects, slight differences between the two patterns can cause false-alarms to be generated. Less mismatch between images is therefore desirable to achieve accurate automatic-defect detection. This paper presents a simple method for adjusting the shape of a reference pattern so that it more closely resembles the shape of an actual circuit pattern which has undergone deformation during the pattern manufacturing process. In this method, a virtual circle scans every pixel in a reference pattern and the center of the circle traces out a locus of the new pattern boundary provided that the area occupied by the pattern in the circle is constant. The method can round-off pattern corners in a flexible manner and can decrease a mismatch of up to 5 pixels to 1 pixel.
