Field-effect semiconductor device and method of producing the same

Abstract

A semiconductor substrate of an IGFET has drain regions, a p-type first body region, a p-type second body region, an n-type first source region, and an n-type second source region, and additionally has multiple pairs of trenches that constitute an IGFET cell. A gate insulating film and a gate electrode are provided inside the trenches. A source electrode is in Schottky contact with the second body region. A pn junction between the second drain region and the first body region is exposed to one of the main surfaces of the semiconductor substrate. The first body region, the second body region, and the first source region are also provided outside the trenches, and an n-type protective semiconductor region is provided. The trenches contribute to miniaturization of the IGFET and to lowering of the on-resistance. The reverse breakdown voltage of the IGFET can be improved by the reduction in contact area between the second body region and the source electrode to the outside from the trenches.