Patent ID: 6765266
Filing Date: 2004-07-20
Classification: H01L

Abstract:
A semiconductor device having a peripheral portion for protecting a cell portion from a surge voltage comprising:a semiconductor substrate having a first conductive type semiconductor layer and a main surface corresponding to a side of the semiconductor layer of the semiconductor substrate; a semiconductor element, which is included in the cell portion, including an electrode formed on the main surface of the semiconductor substrate and a gate formed on the main surface of the semiconductor substrate through a gate isolation film, wherein a current flows via the electrode when a voltage is applied to the gate; a first semiconductor region with a second conductive type formed on a surface portion of the semiconductor layer located in the peripheral portion surrounding the cell portion; a field isolation film formed on the semiconductor layer so as to extend from the first semiconductor region in a further peripheral direction thereof; and field plate rings formed on the semiconductor layer as conductive rings surrounding the cell portion; wherein the first semiconductor region is formed so that a peripheral edge thereof is located between a first field plate ring that corresponds to one of the field plate rings located at an innermost side of the first semiconductor region and a second field plate ring that corresponds to one of the field plate rings adjacent the first plate ring.