Patent ID: 9704952
Date: 2017-07-11
CPC Classifications: H01L

Claim:
1. A semiconductor device, comprising: a vertical MOS transistor including: a protective element including: the second nitride semiconductor layer has a lower impurity concentration of the first conductive type than the first nitride semiconductor layer, the first nitride semiconductor layer has a projection that is protruded toward the second nitride semiconductor layer, wherein the projection has a top face placed at a position to overlap with at least part of the ohmic electrode to the second conductive type, when viewed from a stacking direction of the stacked body, a thickness of the second nitride semiconductor layer in a portion which a bottom face of the trench is in contact with is greater than a thickness of the second nitride semiconductor layer in a portion which the top face of the projection is in contact with, and a thickness of the first nitride semiconductor layer formed at the projection is greater than a thickness of the first nitride semiconductor layer formed under the trench.