Patent ID: 6667515
Filing Date: 2003-12-23
Classification: H01L

Abstract:
A high breakdown voltage semiconductor device including an active area, and a surrounding region surrounding the active area, comprising:a first semiconductor layer of a first conductivity type disposed as a semiconductor active layer common to the active area and the surrounding region, the first semiconductor layer having first and second main surfaces opposite to each other; a second semiconductor layer of a second conductivity type formed in the first main surface of the first semiconductor layer in the active area; a third semiconductor layer of the first conductivity type formed in a surface of the second semiconductor layer; a fourth semiconductor layer disposed on or in the second main surface of the first semiconductor layer in the active area; a gate electrode facing, through a gate insulating film, a portion of the second semiconductor layer between the first semiconductor layer and the third semiconductor layer; a first main electrode electrically connected to the second semiconductor layer and the third semiconductor layer; a second main electrode electrically connected to the fourth semiconductor layer; a ring layer of the second conductivity type formed in the first main surface of the first semiconductor layer and surrounding the active area at a position in the surrounding region adjacent to the active area; a first low-resistivity layer formed in a surface of the ring layer and having a resistivity lower than that of the ring layer, the first low-resistivity layer comprising a metal or polycrystalline silicon of the second conductivity type and having a resistivity of from 1Ã—10âˆ’6 to 1Ã—10âˆ’3 &OHgr;cm; and a connection electrode electrically connecting the first low-resistivity layer to the first main electrode.