Patent ID: 7510925

Claim:
A method of manufacturing a semiconductor device, comprising: the first step of forming a gate electrode over a silicon substrate, with a gate insulating film; the second step of digging down a surface layer of said silicon substrate by etching conducted with said gate electrode as a mask; and the third step of epitaxially growing, on the surface of said dug-down portion of said silicon substrate, a mixed crystal layer including silicon and atoms different in lattice constant from silicon so that said mixed crystal layer contains an impurity with such a concentration gradient that the impurity concentration increases along the direction from said silicon substrate side toward the surface of said mixed crystal layer, wherein, said third step includes epitaxially growing said mixed crystal layer so that said mixed crystal layer contains the impurity with said concentration gradient such that said impurity concentration increases stepwise along the direction from said silicon substrate side toward the surface of said mixed crystal layer.