Recessed Y-gate AlN/GaN/AlGaN DHFET with GaN cap layer at the gate edge

We have proposed and simulated recessed Y-gate AlN/GaN/AlGaN DHFET structure with GaN cap layer at drain side of the gate as well as compared its simulated characteristics with the conventional DHFET. The threshold voltage of the proposed device was increased 0.2V to the positive side. Use of GaN cap at the gate side-wall effectively reduced electric field concentration at the gate edge of the proposed device compared to the conventional one, which also ensured the leakage current of the proposed device was 1 order less than that of conventional device. The forward characteristics of proposed device are slightly degraded due to the recessed gate structure which entered the channel region and 1-nm thin layer of AlN layer.