Abstract
A semiconductor device includes a first nitride semiconductor layer, a second nitride semiconductor layer, a source and a drain, a gate, first p-type doped nitride semiconductor islands, a second p-type doped nitride semiconductor island, a dielectric layer. The second nitride semiconductor layer is disposed on the first nitride semiconductor layer. The source, the drain, and the gate are disposed on the second nitride semiconductor layer. Each of the first p-type doped nitride semiconductor islands forms a protruding profile from the second nitride semiconductor layer. A portion of the drain covers the first p-type doped nitride semiconductor islands such that the portion of the drain is conformal with the first p-type doped nitride semiconductor islands. The second p-type doped nitride semiconductor island is disposed between the second nitride semiconductor layer and the gate. The dielectric layer covers the gate.