US Patent 9000488 Semiconductor device

A semiconductor device includes: an electron transit layer formed with a semiconductor material, the electron transit layer being formed on a semiconductor substrate; an n-type semiconductor layer formed with a semiconductor material having a wider bandgap than the electron transit layer, the n-type semiconductor layer being formed on the electron transit layer; a δ doping area having an n-type impurity doped in a sheet-shaped region, the δ doping area being formed on the n-type semiconductor layer; and a barrier layer formed with a semiconductor material having a wider bandgap than the electron transit layer, the barrier layer being formed on the δ doping area.