SEMICONDUCTOR DEVICE HAVING A BREAKDOWN VOLTAGE HOLDING REGION

摘要

A semiconductor device of the present invention is a semiconductor device having a semiconductor layer comprising a wide band gap semiconductor, wherein the semiconductor layer includes: a first conductivity-type source region, a second conductivity-type channel region and a first conductivity-type drain region, which are formed in this order from the surface side of the semiconductor layer; a source trench lying from the surface of the semiconductor layer through the source region and the channel region to the drain region; a gate insulating film formed so as to contact the channel region; a gate electrode facing the channel region with the gate insulating film interposed therebetween; and a first breakdown voltage holding region of a second conductivity type formed selectively on the side face or the bottom face of the source trench, and the semiconductor device includes a barrier formation layer, which is joined with the drain region in the source trench, for forming, by junction with the drain region, a junction barrier lower than a diffusion potential of a body diode formed by p-n junction between the channel region and the drain region.

主权项

1. A semiconductor device including:
a semiconductor layer comprising a wide band gap semiconductor, and a gate part which is formed at the semiconductor layer and sections the semiconductor layer into a plurality of cells, wherein the cells include: a first MIS transistor structure, which has a first conductivity-type source region, a second conductivity-type channel region and a first conductivity-type drain region arranged in an order from a surface side of the semiconductor layer toward a reverse face side and has a first source trench formed so as to lie from the surface of the semiconductor layer through the source region and the channel region to the drain region with a deepest part thereof; a p-n diode cell, which has a first breakdown voltage holding region of a second conductivity type formed selectively on an inner face of the first source trench and includes a p-n diode constructed by p-n junction between the first breakdown voltage holding region and the drain region; and a Schottky cell in which a first conductivity-type Schottky region united with the drain region is exposed selectively, and the semiconductor device further includes a source electrode, which is formed across the p-n diode cell and the Schottky cell, for forming an ohmic contact with the source region and forming a Schottky barrier lower than a diffusion potential of the body diode formed by p-n junction between the channel region and the drain region, with respect to the Schottky region.