Patent ID: 8110068

Claim:
A gas flow distribution receptacle for providing gas flow to a plasma chamber for forming an ionized gas, the gas flow distribution receptacle having a rounded section comprising: an inner surface defining a reception cavity; an outer surface forming an enclosed end of the rounded section; and a centerpoint on the outer surface, the centerpoint having a longitudinal axis extending therethrough and through the reception cavity, wherein the rounded section further includes a first ring of openings and a second ring of openings adapted to provide flow communication with the plasma chamber, each opening of the first ring of openings extending between the inner surface and the outer surface at a first angle relative to the longitudinal axis mad having a diameter that is substantially identical to a diameter of an adjacent opening in the first ring of openings, the second ring of openings disposed between the first ring of openings and the centerpoint and configured to form a flow curtain over the outer surface of the receptacle to substantially prevent contact between the ionized gas and the outer surface of the receptacle, each opening of the second ring of openings extending between the inner surface and the outer surface at a second angle relative to the longitudinal axis that is less than the first angle and having a diameter that is substantially identical to a diameter of an adjacent opening in the second ring of openings and smaller than the diameters of an opening of the first ring of openings.