Patent ID: 8900364

Claim:
A processing chamber comprising: a lid having a plurality of valves affixed thereto, the plurality of valves operable to supply process gases into the processing chamber; a bottom portion, the bottom portion including a base and side walls extending from the base toward the lid, wherein a surface of the base is configured to support a substrate; and a showerhead affixed to a bottom surface of the lid, a bottom surface of the showerhead comprises a central port, a first ridge surrounding the central port and defining a delivery region accessible to the central port, an annular pump channel surrounding the first ridge, a second ridge surrounding the annular pump channel, and a plurality of holes disposed along an outer periphery of the second ridge, the central port configured for providing process gases into the processing chamber, wherein the first ridge separates the delivery region and the annular pump channel and extends in a direction substantially normal to the surface of the base, and wherein the second ridge separates the annular pump channel and the plurality of holes and extends in the direction substantially normal to the surface of the base.