Patent attributes
One embodiment of the gas delivery assembly comprises a covering member having an expanding channel at a central portion of the covering member and having a bottom surface extending from the expanding channel to a peripheral portion of the covering member. One or more gas conduits are coupled to the expanding channel in which the one or more gas conduits are positioned at an angle from a center of the expanding channel. One embodiment of a chamber comprises a substrate support having a substrate receiving surface. The chamber further includes a chamber lid having a passageway at a central portion of the chamber lid and a tapered bottom surface extending from the passageway to a peripheral portion of the chamber lid. The bottom surface of the chamber lid is shaped and sized to substantially cover the substrate receiving surface. One or more valves are coupled to the passageway, and one or more gas sources are coupled to each valve. In one aspect, the bottom surface of the chamber lid may be tapered. In another aspect, a reaction zone defined between the chamber lid and the substrate receiving surface may comprise a small volume. In still another aspect, the passageway may comprise a tapered expanding channel extending from the central portion of the chamber lid. Another embodiment of the chamber comprises a substrate support having a substrate receiving surface. The chamber further comprises a chamber lid having an expanding channel extending from a central portion of the chamber lid and having a tapered bottom surface extending from the expanding channel to a peripheral portion of the chamber lid. One or more gas conduits are disposed around an upper portion of the expanding channel in which the one or more gas conduits are disposed at an angle from a center of the expanding channel. A choke is disposed on the chamber lid adjacent a perimeter of the tapered bottom surface.