Abstract: An overhead gas distribution electrode forming at least a portion of the ceiling of a plasma reactor has a bottom surface facing a processing zone of the reactor. The electrode includes a gas supply manifold for receiving process gas at a supply pressure at a top portion of the electrode and plural pressure-dropping cylindrical orifices extending axially relative to the electrode from the gas supply manifold at one end of each the orifice. A radial gas distribution manifold within the electrode extends radially across the electrode. Plural axially extending high conductance gas flow passages couple the opposite ends of respective ones of the plural pressure-dropping orifices to the radial gas distribution manifold. Plural high conductance cylindrical gas outlet holes are formed in the plasma-facing bottom surface of the electrode and extend axially to the radial gas distribution manifold.

Abstract: An overhead gas distribution electrode forming at least a portion of the ceiling of a plasma reactor has a bottom surface facing a processing zone of the reactor. The electrode includes a gas supply manifold for receiving process gas at a supply pressure at a top portion of the electrode and plural pressure-dropping cylindrical orifices extending axially relative to the electrode from the gas supply manifold at one end of each the orifice. A radial gas distribution manifold within the electrode extends radially across the electrode. Plural axially extending high conductance gas flow passages couple the opposite ends of respective ones of the plural pressure-dropping orifices to the radial gas distribution manifold. Plural high conductance cylindrical gas outlet holes are formed in the plasma-facing bottom surface of the electrode and extend axially to the radial gas distribution manifold.

Abstract: Apparatus for gas distribution in a semiconductor wafer processing chamber 200 having a roof 228. The roof 228 has a top surface 608 and a bottom surface 312. A recess 314 is disposed within the bottom surface 312 of the roof 228. A gas distribution plate 316 is disposed within the recess 314 and a material layer coating 320 is disposed upon the bottom surfaces 312/500 of the roof 228 and the gas distribution plate 316. The material layer coating 320 and the gas distribution plate 316 each have a plurality of apertures 322/404. The apertures 404 of the gas distribution plate 316 coincide with the apertures 322 in the material layer coating 320. The material layer coating 320 is formed from silicon carbide and most preferably is deposited by chemical vapor deposition (CVD). Both the roof 228 and gas distribution plate 316 are fabricated from silicon carbide.