Acoustic Emission Monitoring and Endpoint for Chemical Mechanical Polishing

Abstract

A chemical mechanical polishing apparatus includes a platen to support a polishing pad, and an in-situ acoustic emission monitoring system including an acoustic emission sensor supported by the platen, a waveguide configured to extending through at least a portion of the polishing pad, and a processor to receive a signal from the acoustic emission sensor. The in-situ acoustic emission monitoring system is configured to detect acoustic events caused by deformation of the substrate and transmitted through the waveguide, and the processor is configured to determine a polishing endpoint based on the signal.

Dependencies are inferred from the claim text.