Patent ID: 8653628

Claim:
A power semiconductor device comprising: a base substrate having one surface and the other surface and formed of a first conductive type drift layer; a second conductive type semiconductor substrate formed on the other surface of the base substrate; a first conductive type diffusion layer formed on one surface of the base substrate and having a concentration higher than that of the first conductive type drift layer; a second conductive type well layer formed on the first conductive type diffusion layer; a trench formed so as to penetrate through the second conductive type well layer and the first conductive type diffusion layer from one surface of the base substrate including the second conductive type well layer in a thickness direction; a first insulating film formed on one surface of the base substrate as well as an inner wall of the trench; and a first electrode formed in the trench, wherein a peak point of an impurity doping profile of the first conductive type diffusion layer is positioned between a region below the second conductive type well layer and a lower surface of the trench.