A novel stepped AlGaN hybrid buffer GaN HEMT for power electronics applications

Abstract

In this paper, a novel p-type gallium nitride (p-GaN) high electron mobility transistor (HEMT) is proposed and investigated for high power electronic applications. In the proposed device, a stepped hybrid Aluminium GaN (AlGaN) buffer layer with low Al content has been introduced to improve the performance of the device. The low aluminium mole concentration decreases the surface defects which reduces the leakage current, thereby increasing the breakdown voltage of the device. To validate the simulation results, calibration of the device models has been performed with experimental results. Results present that the proposed device exhibits high breakdown voltage, high transconductance and low small signal capacitances. The proposed device achieves improvement in breakdown voltage, transconductance and small signal capacitances as compared to the conventional hybrid buffer high electron mobility transistor (HB-HEMT). Furthermore, the processing steps have been proposed for the possible fabrication of the proposed device. Also, the optimization is performed to achieve the optimal device performance with respect to breakdown voltage. Finally, the performance of the proposed device has been compared with the state-of-the-art devices.