Patent ID: 6431953
Filing Date: 2002-08-13
Classification: B24B,G05B

Abstract:
A method for monitoring a chemical-mechanical polishing process comprising:(a) receiving a real-time data signal from a chemical-mechanical polishing process, wherein the real-time data signal pertains to a frictional force, torque, or motor current, (b) submitting the real-time data signal to an algorithm that separates the data signal into a power spectrum of signals with different frequencies whose sum equals that of the real-time data signal, (c) identifying at least one signal component of the power spectrum corresponding to an aspect of the chemical-mechanical polishing process, (d) monitoring the at least one signal component of the power spectrum during the chemical-mechanical polishing process for a change in the amplitude or frequency of the signal component, (e) detecting a change in the amplitude or frequency of the at least one signal component, and (f) altering the chemical-mechanical polishing process in response to the detected change.