Patent ID: 6057558
Filing Date: 2000-05-02
Classification: H01L

Abstract:
A silicon carbide semiconductor device comprising:a semiconductor substrate made up of a low-resistance semiconductor layer of a first conductive type, a high-resistance semiconductor layer of the first conductive type and a first semiconductor layer of a second conductive type;a semiconductor region of the first conductive type formed in a predetermined region of a surface of the first semiconductor layer;a trench passing from a surface of the semiconductor substrate through the semiconductor region and the first semiconductor layer;a second semiconductor layer of the first conductive type consisting of a thin film of silicon carbide formed at least on a surface of the first semiconductor layer at a side face of the trench;a gate insulating film formed at least on a surface of the second semiconductor layer;a gate electrode layer formed on the gate insulating film in the trench;a first electrode layer formed at least on a surface of a part of the semiconductor region at the surface of the semiconductor substrate; anda second electrode layer formed on a rear side of the semiconductor substrate,wherein when a reverse bias voltage is impressed on a pn junction between the first electrode layer and the second electrode layer a pn junction between the high-resistance semiconductor layer and the first semiconductor layer undergoes avalanche breakdown before the second semiconductor layer between the high-resistance semiconductor layer and the semiconductor region suffers punch-through.