Patent ID: 8653588

Claim:
A semiconductor device comprising: a first semiconductor layer of a first conductivity type; a second semiconductor layer of a second conductivity type formed on one of surfaces of the first semiconductor layer; trenches formed on the other surface of the first semiconductor layer opposite to the second semiconductor layer; a semiconductor protruding part whose side surfaces are sandwiched between the trenches and formed on a rest of the surface of the first semiconductor layer other than the surface on which the trenches are formed; a third semiconductor layer of the second conductivity type formed on a surface of the semiconductor protruding part at a predetermined location; a fourth semiconductor layer of the first conductivity type partially formed on a surface of the third semiconductor layer and having a higher impurity concentration than the first semiconductor layer; a gate insulating layer disposed on a part of an inner wall of the trenches; a first interlayer insulating layer disposed on a rest of the inner wall of the trenches other than the inner wall on which the gate insulating layer is disposed; a first conductive layer, at least a part thereof facing the fourth semiconductor layer via the gate insulating layer; a second conductive layer formed on a surface of the first interlayer insulating layer; a second interlayer insulating layer, at least a part thereof covering at least a part of a surface of the second conductive layer; a third conductive layer, at least a part thereof being formed on surfaces of the third semiconductor layer and the fourth semiconductor layer and electrically connected to the fourth semiconductor layer; a contacting part electrically connecting the third conductive layer and the third semiconductor layer; a fourth conductive layer formed on a surface of the second semiconductor layer, wherein a part of the surface of the semiconductor protruding part includes a part of the first semiconductor layer; and wherein the third semiconductor layer covers a circumference of side-wall of the first conductive layer.