A PROCESSING CHAMBER AND METHOD FOR CONFINING PLASMA

摘要

A substrate processing chamber, particularly a chemical vapor deposition (CVD) chamber used both for thermal deposition of a conductive material and a subsequently performed plasma process. The invention reduces thermal deposition of the conductive material on peripheral portions of the pedestal supporting a wafer and in a pumping channel exhausting the chamber. A peripheral ring placed on the pedestal, preferably also used to center the wafer, is thermally isolated from the pedestal so that its temperature is kept substantially lower than that of the wafer. The processing chamber includes a chamber lid assembly having an isolator ring member that has a sloping surface for confining the plasma within a processing zone of the processing chamber while the wafer is being processed therein. A method for forming a CVD layer on a wafer comprising elevating the pedestal until an upper pedestal surface of the pedestal extends above a lower edge of the isolator ring member.