Abstract: A plasma processing chamber includes a substrate holder and a gas distribution plate having an inner surface facing the substrate holder, the inner surface being maintained below a threshold temperature to minimize process drift during processing of substrates. The inner surface is cooled by adding a heat transfer gas such as helium to process gas supplied through the gas distribution plate. The chamber can include a dielectric window between an antenna and the gas distribution plate. The control of the temperature of the inner surface facing the substrate minimizes process drift and degradation of the quality of the processed substrates during sequential processing of the substrates such as during oxide etching of semiconductor wafers.