Patent ID: 6844592

Claim:
A semiconductor device comprising: a first—first conductivity type semiconductor layer which includes a cell region portion and a junction terminating region portion, said junction terminating region portion being a region portion which is positioned in an outer periphery of the cell region portion to maintain a breakdown voltage by extending a depletion layer to attenuate an electric field; a second-first conductivity type semiconductor layer which is formed on one surface of the first—first conductivity type semiconductor layer; a first main electrode which is electrically connected to the second-first conductivity type semiconductor layer; first-second conductivity type semiconductor layers which are formed in the cell region portion of the first—first conductivity type semiconductor layer in substantially vertical directions to said one surface of the first—first conductivity type semiconductor layer, respectively, and which are periodically disposed in a first direction which is an arbitrary direction parallel to said one surface; a second—second conductivity type semiconductor layer which is selectively formed in the other surface portion of the first—first conductivity type semiconductor layer so as to contact the first-second conductivity type semiconductor layers; a third-first conductivity type semiconductor layer which is selectively formed in the surface portion of the second—second conductivity type semiconductor layer; a second main electrode which is formed so as to contact the second—second conductivity type semiconductor layer and the third-first conductivity type semiconductor layer; a control electrode which is formed on the surface of the first—first conductivity type semiconductor layer sandwiched by the adjacent second—second conductivity type semiconductor layers, the surface of the adjacent second—second conductivity type semiconductor layers and the surface of the third-first conductivity type semiconductor layer, with a gate insulating film interposed therebetween; and third-second conductivity type semiconductor layers which are formed in the junction terminating region portion and are periodically disposed in at least one direction of the first direction and a second direction perpendicular to the first direction.