Method and apparatus for cleaning semiconductor etching machines

A method and apparatus for cleaning polymer contamination within etching machines during the processing of semiconductor wafers includes the use of a polygonal cleaning wafer on an electrode within the etching chamber during an oxygen plasma cleaning operation. Normal etching of semiconductor wafers in the chamber results in a build-up of deposits (polymer contamination) of the semiconductor wafer etch processing on walls of the etching chamber and on the electrode. The polygonal cleaning wafer, which is typically octagonal, exposes an annular ring of on a supporting electrode adjacent to each flat of the octagonal cleaning wafer. The cleaning wafer is preferably made of the same material as the interior of the etching machine to avoid contamination by foreign elements The presence of the cleaning wafer enables sensing circuits within the etching machine to activate radio frequency power which is used to create an oxygen plasma.