Simulation of a Normally-off HEMT Transistor Based on a GaN/AlGaN with a p-Gate

We perform the numerical simulation of the characteristics of normally-off GaN/AlGaN HEMT transistors with a p -gate. The dependences of the threshold voltage on the thickness of the main AlGaN barrier and additional spacer and stop AlN layers are determined. The effect of the incomplete compensation of the spontaneous charge during passivation on the output characteristics of the transistor is analyzed. The effect of the ohmic resistance of the source on the saturation current of the transistor is studied. It is shown that the saturation current with the optimal design parameters can reach 1 A/mm at a gate voltage of V g ~ 3 V.