Patent ID: 8575687

Claim:
A semiconductor device comprising: a semiconductor layer of one conductivity type including a plurality of trenches arranged with predetermined spaces, so that each region between the neighboring trenches becomes a channel; and a plurality of embedded electrodes each of which is formed on an inner surface of each of the plurality of trenches via an insulator film so as to fill in each of the plurality of trenches, the semiconductor device switching between an on state and an off state according to a voltage applied to the plurality of embedded electrodes, wherein the plurality of trenches have substantially the same width and substantially the same depth as one another, wherein all semiconductor material adjacent the trenches is of the one conductivity type, wherein a concentration of an impurity of the one conductivity type is substantially the same in the channel of the semiconductor layer and in a region of the semiconductor layer on a bottom side of the plurality of trenches, wherein the plurality of embedded electrodes include two types, which are a first embedded electrodes and second embedded electrodes to which voltages are applied separately, and wherein in the off state, each depletion layer formed around any of the plurality of trenches blocks a region between the neighboring trenches, and in the on state, a depletion layer, formed around any of the plurality of trenches in which the first type of embedded electrode is embedded, disappears to permit current to flow through the region between the neighboring trenches.