Patent ID: 7303979

Claim:
A semiconductor device manufacturing method in which a semiconductor layer is deposited on an active region as an epitaxial layer and is deposited on a separation silicon oxide layer as a polycrystalline layer in a vapor-phase growth process in which a silicon-germanium mixed crystal layer is deposited on a semiconductor substrate of a single crystal silicon substrate across said active region exposed to said single crystal silicon substrate surface and said separation silicon oxide layer for separating said active region, the semiconductor device manufacturing method characterized in that a vapor-phase growth method comprises the steps of: a first step of introducing silicon raw material gas and germanium raw material gas into a reaction furnace to thereby form a first semiconductor layer of a silicon-germanium mixed crystal film; a second step of introducing silicon raw material gas, germanium raw material gas, and an impurity raw material gas into said reaction furnace to thereby form a second semiconductor layer of a silicon-germanium mixed crystal layer; and, a third step of introducing silicon raw material gas and an impurity raw material gas into said reaction furnace to thereby form a third semiconductor layer of a silicon layer, wherein germanium concentration in said epitaxial layer of said first semiconductor layer deposited at said first step is 7 atom % and a germanium concentration is made constant with respect to the thickness direction of said first semiconductor layer of a silicon-germanium mixed crystal film, and wherein a laminating semiconductor layer formed by said first, second and third steps is deposited on a portion formed on an active region exposed to said single crystal silicon substrate surface as a single crystal semiconductor layer and is deposited on a portion formed on said separation silicon oxide layer as a polycrystalline semiconductor layer.