Patent ID: 8368141
Filing Date: 2013-02-05
Classification: H01L,H02M

Abstract:
1. A high breakdown voltage semiconductor device, comprising: a support substrate; a first conductive type semiconductor layer formed on the support substrate across a dielectric layer; a first conductive type drain layer, with an impurity concentration higher than that of the semiconductor layer, on the semiconductor layer; a first conductive type buffer layer, formed on the surface of the semiconductor layer so as to envelop the drain layer, and with an impurity concentration between those of the semiconductor layer and drain layer; a first conductive type source layer with an impurity concentration higher than that of the semiconductor layer, separated from the drain layer, and formed so as to surround a periphery thereof; a second conductive type well layer formed so as to envelop the source layer; a gate electrode formed on the source layer, the second conductive type well layer, and the semiconductor layer and interposed between the well layer and buffer layer, across a gate insulating film; a drain electrode electrically connected to the drain layer; and a source electrode electrically connected to the source layer, wherein the planar shape of the drain layer and buffer layer is a continuous ring or a non-continuous ring comprising slits between portions of the buffer layer.