High electron mobility transistor and method of manufacturing the same

A high electron mobility transistor comprising:

• a channel layer;
• a barrier layer on the channel layer and configured to induce formation of a two-dimensional electron gas (2DEG) in the channel layer;
• a p-type semiconductor layer on the barrier layer;
• a first passivation layer on the barrier layer and including a quaternary material of Al, Ga, O, and N;
• a gate electrode on the p-type semiconductor layer;
• and
• a source electrode and a drain electrode on both sides of the barrier layer, respectively, and separated from the gate electrode, and
• wherein the first passivation layer is interfaced with a top surface of the barrier layer.