Abstract: An apparatus and a method for reducing particle contamination by a polymeric film in a plasma etcher are described. In the apparatus for dry etching a wafer, a wafer holder and a ring member positioned juxtaposed to the holder are provided wherein the ring member is used to confine a plasma cloud generated in the chamber cavity onto an exposed surface of the wafer. The ring member has surface areas that is substantially exposed to the chamber interior, the surface areas are roughened to a depth between about 1 &mgr;m and about 10 &mgr;m between peaks and valleys formed in the roughened surfaces by either a sand-blasting method or by a chemical etching method. When the sand-blasting method is utilized to roughen the surface of the ring member, i.e., a focus ring in a reactive ion etching apparatus, particles having a mesh size between 200 mesh and 80 mesh may be suitably used.

Abstract: A composite shadow ring for use in a plasma etch chamber that has a longer service life and can be readily replaced at a lower cost and a method for using such ring are disclosed. The composite shadow ring is constructed by a larger outer ring and a smaller inner ring which may be fabricated of quartz. The smaller inner ring has an upper planar surface for partially supporting an edge of an wafer and for exposing substantially to the gas plasma in the etch chamber. When the upper planar surface of the smaller inner ring is corroded by the gas plasma, the inner ring may be turned upside-down and reused, or when both sides have been corroded it can be readily replaced at a low cost without replacing the more expensive outer ring. The present invention composite shadow ring therefore presents a substantially lower cost shadow ring for use in an etching process than that possible with the conventional quartz shadow rings.