Patent ID: 7960782

Claim:
A nitride semiconductor device comprising: a nitride semiconductor structure portion including a first layer made of an n-type group III nitride semiconductor, a second layer made of a group III nitride semiconductor containing a p-type impurity provided on the first layer and an n-type region formed on a part of the second layer such that the nitride semiconductor structure portion has a wall surface extending over the first layer, a body region of the second layer other than the n-type region and the n-type region; a gate insulating film formed such that the gate insulating film is opposed to the body region on the wall surface; a gate electrode formed such that the gate electrode is opposed to the body region through the gate insulating film; a source electrode formed such that the source electrode is electrically connected to the n-type region; a drain electrode formed such that the drain electrode is electrically connected to the first layer; and a body electrode formed such that the body electrode is electrically connected to the body region; wherein the n-type region and the body region are exposed from an outermost surface of the second layer, the source electrode is in touch with an exposure portion of the n-type region to the outermost surface, the body electrode is provided separately from the source electrode such that the body electrode is in touch with an exposure portion of the body region to the outermost surface, the nitride semiconductor structure portion further includes a third layer, formed on a semiconductor surface portion of the body region on the wall surface, having conductivity different from that of the body region, and extending over the n-type region and the first layer along the wall surface, and the gate insulating film is interposed between the third layer and the gate electrode.