Patent ID: 8716147

Claim:
A manufacturing method of a semiconductor device, comprising steps of: (a) loading a plurality of substrates into a reaction vessel including a process tube and a manifold that supports the process tube, and arranging the plurality of substrates loaded in the reaction vessel; (b) carrying out a pre-process by supplying a pre-process gas from a manifold side toward a process tube side within the reaction vessel to remove a natural oxide film or a contaminant from the plurality of substrates; (c) carrying out a main-process by supplying a main-process gas from the manifold side toward the process tube side within the reaction vessel to form a thin film on the plurality of substrates subjected to the pre-process; and (d) unloading the plurality of substrates subjected to the main-process from the reaction vessel, wherein, in the step (b), mixtures of a hydrogen-containing gas, a silicon-containing gas and a chlorine-containing gas are supplied as the pre-process gas from at least one position in an area of an inside of the reaction vessel corresponding to the manifold, and from at least one position in an upper area of an area located between the process tube and the plurality of substrates and corresponding to a substrate arrangement area, and flow rate ratios or concentration ratios of the mixtures are different in at least one position and the other positions among positions from which the pre-process gas is supplied.