Semiconductor device and method of manufacturing semiconductor device

Abstract

A semiconductor device includes: a semiconductor base substrate including a semiconductor layer; a first main electrode; a second main electrode; a plurality of peripheral trenches formed on a surface of the semiconductor layer and having bottom portions covered by the semiconductor layer in a peripheral region; and a plurality of in-trench electrodes each embedded in each of the plurality of peripheral trenches byway of an insulation layer formed on an inner surface of the each peripheral trench, wherein the semiconductor base substrate further includes, in the peripheral region, a plurality of second conductive type floating regions disposed in the semiconductor layer at a depth position deeper than the bottom portions of the peripheral trenches in a spaced apart manner from the peripheral trenches and having a potential in a floating state.