Patent ID: 8120104

Claim:
A semiconductor device comprising: a substrate having a first conductivity-type semiconductor layer in the surface layer; a first first-conductivity-type high-concentration diffusion layer, formed in the surface layer of said first conductivity-type semiconductor layer, which has a higher impurity concentration than that of said first conductivity-type semiconductor layer; a first second-conductivity-type high-concentration diffusion layer, formed in the surface layer of said first conductivity-type semiconductor layer, which is in contact with said first first-conductivity-type high-concentration diffusion layer; a second conductivity-type low-concentration drift layer, formed in the surface layer of said first conductivity-type semiconductor layer, which has a lower impurity concentration than that of said first second-conductivity-type high-concentration diffusion layer; a gate insulating film formed so as to cover the surface of said first conductivity-type semiconductor layer between said first second-conductivity-type high-concentration diffusion layer and said second conductivity-type low-concentration drift layer, and a portion of said second conductivity-type low-concentration drift layer; a gate electrode formed over said gate insulating film; a second first-conductivity-type high-concentration diffusion layer formed in the surface layer of said second conductivity-type low-concentration drift layer; a second conductivity-type sinker layer, of which at least a portion is formed in the surface layer of said first conductivity-type semiconductor layer, and which is separated from both said second conductivity-type low-concentration drift layer and said second first-conductivity-type high-concentration diffusion layer; a second second-conductivity-type high-concentration diffusion layer formed in the surface layer of said second conductivity-type sinker layer; and an interconnect, formed over said first conductivity-type semiconductor layer, which connects said second first-conductivity-type high-concentration diffusion layer and said second second-conductivity-type high-concentration diffusion layer to each other.