Applied Materials, Inc.
PROFILE CONTROL DURING POLISHING OF A STACK OF ADJACENT CONDUCTIVE LAYERS

Abstract:

During polishing of a stack of adjacent conductive layers on a substrate, an in-situ eddy current monitoring system measures sequence of characterizing values. A polishing rate is repeatedly calculated from the sequence of characterizing values repeatedly, one or more adjustments for one or more polishing parameters are repeatedly calculated based on a current polishing rate using a first control algorithm for an initial time period, a change in the polishing rate that meets at least one first predetermined criterion that indicates exposure of the underlying conductive layer is detected, and one or more adjustments for one or more polishing parameters are calculated based on the polishing rate using a different second control algorithm for a subsequent time period after detecting the change in the polishing rate.