Patent ID: 8343307

Claim:
A processing chamber comprising a showerhead including a grounded electrode having a recess in its top center to hold a top electrode through an isolator ring; wherein the top electrode has a passage formed there through with a gradually increasing inner diameter; wherein the improvement comprises: a hollow cylinder having a top wall, a bottom wall, an inner diameter wall and an outer diameter wall; a disc having a top surface and a lower surface, the top surface coupled to the inner diameter wall, the lower surface coupled to the bottom wall, the disc having a plurality of apertures connecting the lower surface to the top surface; an annular mounting flange extending from the outer diameter wall of the hollow cylinder, the mounting flange having an upper surface and a lower surface, the upper surface coplanar with the top wall of the hollow cylinder, the lower surface having an elevation above the top surface of the disc, wherein the hollow cylinder, the disc and the annular mounting flange are formed as a one piece structure; and a channel circumscribing and positioned coplanar with the disc the said annular mounting flange supporting the grounded electrode, wherein the plurality of apertures of the disk are in fluid communication with the passage of the top electrode.