Abstract
A semiconductor device includes a first semiconductor layer, a second semiconductor layer, a source, a drain, a gate structure, and a first p-type doped III-V compound/nitride semiconductor layer. The second semiconductor layer is disposed on the first semiconductor layer and has a bandgap greater than a bandgap of the first semiconductor layer. The source and the drain are disposed on the second semiconductor layer. The gate structure is disposed on the second semiconductor layer and between the source and the drain. The first p-type doped III-V compound layer is disposed on the second semiconductor layer and between the gate structure and the drain with the drain at least partially covering the p-doped layer such that the first p-type doped III-V compound layer and the drain are electrically coupled with each other.