Patent ID: 8853709

Claim:
A field effect transistor (FET) comprising: a III-Nitride channel layer comprising GaN; a III-Nitride barrier layer on the channel layer, wherein the barrier layer has an energy bandgap greater than the channel layer; a source electrode electrically coupled to one of the III-Nitride layers; a drain electrode electrically coupled to one of the III-Nitride layers; a gate trench between the source electrode and the drain electrode, the gate trench extending into the channel layer, wherein a bottom of the gate trench is in the channel layer; an AlN layer in the gate trench at the bottom of the gate trench; an insulator layer comprising at least one SiN layer in the gate trench, the SiN layer in direct contact with the AlN layer; and a gate electrode in contact with the insulator layer; wherein the AlN layer is in contact with one of the III-Nitride layers; and wherein the AlN layer has a thickness ranging from 1.5 nanometers to 50 nanometers.