Patent ID: 6902622

Claim:
A wafer processing system comprising: a processing chamber containing a substrate holder for receiving at least one semiconductor substrate; a heating device in communication with the processing chamber; a plurality of gas inlets for flowing gas into the processing chamber over the surface of a semiconductor substrate, wherein at least certain of the gas inlets are configured to flow a gas over an edge zone on a semiconductor substrate, at least certain of the gas inlets are configured to flow a gas over a middle zone on a semiconductor substrate, and at least certain of the gas inlets are configured to flow a gas over a center zone on a semiconductor substrate; the plurality of gas inlets include a longitudinal section and a common lateral section that includes a common plenum such that gases flow upwards or downwards through the longitudinal section prior to being directed across the semiconductor substrate by the lateral section; a gas supply configured to control flow rate of gases supplied to the gas inlets to selectively control the flow of gases over the edge zone, the middle zone, and the center zone of a semiconductor substrate; and a gas exhaust system configured to exhaust gases from the process chamber.