| abstract |
The nitride semiconductor device includes a nitride semiconductor layer 12, a gate insulating film 28, a source electrode 20, a drain electrode 30, and a gate electrode 26. The nitride semiconductor layer 12 includes a first body layer, a second body layer, a drift layer 44, a first source layer, and a second source layer. The drift layer 44 includes a first drift layer 46 extending from a position in contact with the bottom surface of the first body layer to a position in contact with the bottom surface of the second body layer, And an electric field relaxation layer 48 which is in contact with the lower end of the side surface of the body layer and is in contact with the first drift layer 46 and has a second conductive impurity concentration lower than that of the first drift layer 46. |