ADAPTIVELY TRACKING SPECTRUM FEATURES FOR ENDPOINT DETECTION

摘要

A method of controlling polishing includes polishing a substrate; Monitoring the substrate with an in-situ monitoring system during polishing; Generating a sequence of values from measurements from the in-situ monitoring system; Fitting a non-linear function to a sequence of values; Determining an expected time at which the non-linear function reaches the target value; And determining at least one of an adjustment to the polishing rate or a polishing endpoint based on the expected time.