Convex insert ring for etch chamber

Abstract

A new and improved insert ring for a wafer support inside a processing chamber for the processing, particularly dry etching, of semiconductor wafer substrates. The insert ring includes a generally convex inner surface which faces the wafer support and defines a gap or berline wall between the insert ring and the wafer support. In one embodiment, the convex inner surface is convexly-tapered. In another embodiment, the convex inner surface is convexly-curved. Throughout etching of multiple successive substrates on the wafer support, accumulations of polymer material on the inner surface of the insert ring are prevented or at least substantially reduced. Consequently, polymer peeling is eliminated or reduced and operational intervals for the processing chamber or system between periodic maintenance or cleanings, are prolonged.