A deposition chamber for delivering gases to a substrate or wafer for processing of said substrate or wafer is provided. The injector is provided comprising an elongated member with end surfaces and at least one gas delivery surface extending along the length of the member and which includes a number of first elongated passages formed therein for received a gas. Also formed within the member are a number of thin distribution channels which extend between the first elongated passages and the gas delivery surface. In another embodiment, the injector further includes at least one second elongated passage formed therein for receiving an etchant species. Metering tubes may be inserted into each elongated passage and are spaced from the walls of said passages and extend between the ends. The deposition chamber includes at least one injector as described above; a plurality of vent blocks having end surfaces and at least one elongated external surface extending along the length of each of the vent blocks; and a support positioned beneath the injector and vent blocks, creating a deposition region there between. The vent blocks are positioned adjacent one on each side of the injector, and spaced from the injector to define exhaust channels there between for removing the gas.