Patent ID: 7777292

Claim:
A semiconductor device, comprising: a semiconductor substrate of a first conductivity type having a top surface and a bottom surface; a semiconductor layer of a first conductivity type formed on the top surface of the semiconductor substrate, and having an active region and an edge termination region surrounding the active region; a first semiconductor region of a second conductivity type formed in the edge termination region adjacent to an edge of the active region, the second conductivity type being opposite the first conductivity type; a second semiconductor region of the second conductivity type buried in the edge termination region in a mesh shape substantially in parallel with a surface of the semiconductor layer so as to include a plurality of concentric circular layers of the second conductivity type that are coupled by radially extending layers of the second conductivity type; a fourth semiconductor region of the first conductivity type formed on a peripheral edge surface of the semiconductor layer so as to surround the first semiconductor region with a space and has an impurity concentration higher than that of the semiconductor layer; a first electrode formed on the active region of the semiconductor layer and a part of the first semiconductor region; an insulating layer covering the semiconductor layer so as to surround the first electrode; and a second electrode formed on the bottom surface of the semiconductor substrate.