Abstract
The embodiment of the invention discloses a semiconductor device and a manufacturing method thereof. A semiconductor device includes a semiconductor layer, a first doped nitride semiconductor layer disposed on the semiconductor layer, and a second doped nitride semiconductor layer disposed on the first doped nitride semiconductor layer. The semiconductor device also includes an undoped nitride semiconductor layer between the semiconductor layer and the first doped nitride semiconductor layer. The undoped nitride semiconductor layer has a first surface in contact with the semiconductor layer and a second surface in contact with the first doped nitride semiconductor layer.