Patent ID: 6709312
Filing Date: 2004-03-23
Classification: B24B

Abstract:
A method for monitoring a polishing condition of a surface of a wafer in a polishing process, the method comprising the steps ofproviding a wafer to be polished, the wafer having at least one optically distinguishable feature below a transparent or translucent layer to be polished; selecting one or more of said features for monitoring; measuring an optical contrast profile across one or more of said selected features; determining the polishing condition of the surface of the wafer on the basis of the measured contrast profile; and repeating the steps of measuring the optical contrast profile and determining the polishing condition until a predetermined polishing condition is reached; determining the intensity and the sharpness of the contrast profile; and comparing the determined intensity and sharpness to predetermined values, to decide whether said predetermined polishing condition is reached.