Patent ID: 7780789

Claim:
A chamber for processing substrates, comprising: a substrate support comprising a substrate receiving surface; and a chamber lid assembly comprising: an expanding channel extending along a central axis at a central portion of the chamber lid assembly; a tapered bottom surface extending from the expanding channel to a peripheral portion of the chamber lid assembly, wherein the tapered bottom surface is shaped and sized to substantially cover the substrate receiving surface; a first conduit coupled to a first gas passageway, wherein the first gas passageway surrounds the expanding channel and comprises a first plurality of inlets extending into the expanding channel; and a second conduit coupled to a second gas passageway, wherein the second gas passageway surrounds the expanding channel and comprises a second plurality of inlets extending into the expanding channel, and the first plurality of inlets and the second plurality of inlets are positioned to provide a circular gas flow pattern through the expanding channel.