Patent ID: 8030706

Claim:
A power semiconductor device including a device part where a current flows in an on-state, and a terminal part which is provided around the device part, the device comprising: a first semiconductor layer of a first conductivity type; second semiconductor layers of the first conductivity type and third semiconductor layers of a second conductivity type, formed on the first semiconductor layer, and alternately arranged along a direction parallel to a surface of the first semiconductor layer; a fourth semiconductor layer of the second conductivity type, selectively formed on surfaces of the second and third semiconductor layers; a fifth semiconductor layer of the first conductivity type, selectively formed on a surface of the fourth semiconductor layer; a control electrode formed on the second, fourth, and fifth semiconductor layers via an insulating layer; a first main electrode electrically connected to the fourth and fifth semiconductor layers; and a second main electrode electrically connected to the first semiconductor layer, wherein the device part is provided with a first region and a second region, each of which includes at least one of the second semiconductor layers and at least one of the third semiconductor layers, the first region and the second region being adjacent to each other in a direction parallel to the surface of the first semiconductor layer, and with regard to a difference value ΔN (=N A −N B ) obtained by subtracting an impurity amount N B per unit length of each of the third semiconductor layers from an impurity amount N A per unit length of each of the second semiconductor layers, a difference value ΔN C1 which is the difference value ΔN in the first region of the device part, a difference value ΔN C2 which is the difference value ΔN in the second region of the device part, and a difference value ΔN T which is the difference value ΔN in the terminal part satisfy a relationship of ΔN C1 >ΔN T >ΔN C2 .