Applied Materials, Inc.
PRESSURE SIGNALS WITH DIFFERENT FREQUENCIES DURING FRICTION MONITORING TO PROVIDE SPATIAL RESOLUTION

Abstract:

A method of polishing includes holding a substrate with a carrier head against a polishing surface of a polishing pad, generating relative motion between the substrate and polishing pad, applying a first pressure in a first cyclic waveform having a first frequency to a first region of the substrate, applying a second pressure in a second cyclic waveform having a different second frequency to a different second region of the substrate, during polishing of the substrate, monitoring the substrate with an in-situ motor torque monitoring system to generate a sequence of measured values, and determining a relative contribution to the sequence of measured values from the first region and second region based on distinguishing the first frequency from the second frequency.