Design and Fabrication of Normally-on and Normally-off Ultrathin AlN-based Transistors

This article demonstrates simulation of normally-off and normally-on GaN-based transistors with ultrathin AlN layer. Influence of the heterostructure parameters on the transistor’s characteristics has been researched. Verification of modeling parameters by experimental data has been carried out. It’s shown that polarization charge at the AlN/GaN interface and the transistor characteristics strongly depend on AlN thickness and the heterostructure growth conditions. The device with 3 nm AlN layer is normally-off and has the maximum drain current about 430 mA/mm at 0 V on the gate electrode. At the same time the normally-on one with 7 nm AlN layer has about 900 mA/mm maximum drain current at 3 V gate voltage.