Patent ID: 7832354

Claim:
A plasma reactor for processing a workpiece, comprising: a chamber enclosure comprising a sidewall and a ceiling; a workpiece support in said chamber having a workpiece support surface facing said ceiling; a cathode liner surrounding said workpiece support and having a top surface and a base and having plural internal gas flow channels extending from said base to said top surface; a gas supply plenum at said base coupled to each of said internal gas flow channels; and a process ring overlying said top surface of said cathode liner and having an inner edge that is adjacent a peripheral edge of said workpiece support surface, said process ring comprising an upper process ring and a lower process ring; an annular feed chamber defined amongst: (a) said top surface of said cathode liner, (b) a radially outwardly facing surface of said upper process ring and (c) a radially outwardly facing surface of said lower process ring, wherein each of said plural internal gas flow channels is open at said top surface to said annular feed chamber; a gas injector in said process ring formed as a gap between said upper and lower process rings and having a gas injection path through said inner edge and directed toward a zone overlying said workpiece support surface, said gas injector being coupled to said plural internal gas flow channels through said annular feed chamber; and a gas supply system coupled to said gas supply plenum.