US Patent 7728354 Semiconductor device

A semiconductor device includes: a first semiconductor layer of p-type AlxGa1-xN (0≦x≦1); a second semiconductor layer of n-type AlyGa1-yN (0<y<1, x<y) formed on the first semiconductor layer; a control electrode formed on the second semiconductor layer; a first main electrode connected to the first semiconductor layer and the second semiconductor layer; and a second main electrode connected to the second semiconductor layer. An interface between the first semiconductor layer and the second semiconductor layer has a surface orientation of (1-101) or (11-20).