Patent attributes
A semiconductor device includes a nucleation layer, a first buffer layer, a first nitride-based semiconductor layer, and a second buffer layer. The nucleation layer includes a compound which includes a first element. The first buffer layer includes a III-V compound which includes the first element. A concentration of the first element varies with respect to a first reference point within the first buffer layer. The first nitride-based semiconductor layer is disposed on the first buffer layer. The second buffer layer includes a III-V compound which includes a second element different than the first element. The second buffer layer is disposed on and forms an interface with the first nitride-based semiconductor layer. A concentration of the second element varies to cyclically oscillate as a function of a distance within a thickness of the second buffer layer, which occurs with respect to a second reference point within the second buffer layer.