Patent ID: 7064384

Claim:
A semiconductor device comprising: a first main electrode; a second main electrode; a semiconductor base region of a first conductivity type; a gate electrode provided in a trench through an insulating film, the trench being formed to penetrate the semiconductor base region; and a first semiconductor region of a second conductivity type provided under the semiconductor base region, a second semiconductor region of a first conductivity type provided under the first semiconductor region, a third semiconductor region of a second conductivity type provided under the second semiconductor region, and a fourth semiconductor region of a second conductivity type provided on the semiconductor base region, the first main electrode being provided on the fourth semiconductor region and the second main electrode being provided under the third semiconductor region, a flow of a current between the first and second main electrodes when a voltage of a predetermined direction is applied between these electrodes being controllable in accordance with a voltage applied to the gate electrode, and a depleted region extending from a junction between the first and the second semiconductor regions reaching the trench, wherein a bottom of the trench is provided within the second semiconductor region.