High frequency noise performance of AlGaN/InGaN/GaN HEMTs with AlN interlayer

A systematic physical model of AlGaN/InGaN/GaN heterojunction high electron mobility transistors (HEMTs) is established, and a novel AlGaN/InGaN/GaN HEMT structure with AlN interlayer is proposed in this paper. Polarization effect, interface state, surface state, and traps are considered, and the 2D-numerical simulation results of AlGaN/InGaN/GaN HEMT fit the measured results well. The high frequency noise performance of AlGaN/AlN/InGaN/GaN HEMTs are studied based on the established model. The results show that, because of the enhancement of carrier confinement by inserting AlN layer, the minimum noise figure improved 0.5 dB at 8 GHz, the noise conductance reduced about 50%, and the cut-off frequency increased about 17%.