Nitride-based semiconductor device and method for manufacturing the same

A nitride-based semiconductor device, comprising:

• a first nitride-based semiconductor layer comprising a drift region and at least two doped barrier regions defining an aperture in the drift region;
• a nitride-based multiple semiconductor layer structure disposed over the first nitride-based semiconductor layer and having a first heterojunction and a second heterojunction which are separated from each other, wherein the nitride-based multiple semiconductor layer structure comprises:
• a second nitride-based semiconductor layer disposed over the first nitride-based semiconductor layer, and a third nitride-based semiconductor layer disposed on the second nitride-based semiconductor layer, and having a bandgap higher than a bandgap of the second nitride-based semiconductor layer, and having a material different from a material of the second nitride-based semiconductor layer, so as to form the first heterojunction therebetween, wherein two-dimensional electron gas (2DEG) regions are generated adjacent to the first heterojunction and the second heterojunction to transport carriers laterally;
• a gate electrode received by the nitride-based multiple semiconductor layer structure and vertically aligning with the aperture in the drift region, wherein the second nitride-based semiconductor layer has a recess to receive the gate electrode and a bottom separating the gate electrode from the first nitride-based semiconductor layer, and a bottom surface of the recess is located between a top surface of the second nitride-based semiconductor layer and a bottom surface of the second nitride-based semiconductor layer;
• a gate insulator layer disposed between the nitride-based multiple semiconductor layer structure and the gate electrode;
• and
• a source electrode disposed over the first nitride-based semiconductor layer and abutting against the first and second heterojunctions of the nitride-based multiple semiconductor layer structure, wherein the source electrode is electrically coupled with the 2DEG regions adjacent to the first heterojunction and the second heterojunction.