摘要 |
PROBLEM TO BE SOLVED: To provide a method and an apparatus for detecting a proper endpoint. SOLUTION: An apparatus and a method bring a surface of a substrate into contact with a polishing pad with a window, cause relative motion between the substrate and the polishing pad, and direct a light beam through the window so that the motion of the polishing pad relative to the substrate causes the light beam to move in a path across the substrate. An extreme intensity measurement is derived from a plurality of intensity measurements made as the light beam moves across the substrate. The beam sweeps across the substrate a plurality of times to generate a plurality of extreme intensity measurements, and a polishing endpoint is detected based on the plurality of extreme intensity measurements. |