METHODS AND APPARATUS FOR DETERMINING THE ENDPOINT OF A CLEANING OR CONDITIONING PROCESS IN A PLASMA PROCESSING SYSTEM

摘要

A method of determining an endpoint of a process by measuring a thickness of a layer, the layer being deposited on the surface by a prior process is disclosed. The method includes providing a sensor that is coplanar with the surface, wherein the sensor is configured to measure the thickness. The method also includes exposing the plasma chamber to a plasma, wherein the thickness is changed by the exposing, and determining the thickness as a function of time. The method further includes ascertaining a steady state condition in the thickness, the steady state condition being characterized by a substantially stable measurement of the thickness, a start of the steady state condition representing the endpoint.