POLISHING END POINT DETECTION FOR SUBSTRATE

摘要

PROBLEM TO BE SOLVED: To provide a technique that can detect a polishing end point with the use of a principle different from frictional force and light reflectance. SOLUTION: A two-dimensional image of a polished surface of a substrate is acquired, and the two-dimensional image is analyzed to compute entropies H1 and H2 of the two-dimensional image. The entropies H1 and H2 are used to determine a polishing end point of the substrate. The entropies H1 and H2 can be replaced with another image feature such as a difference statistic of the image.