Suppression of leakage current of p-GaN gate AlGaN/GaN HEMTs with beta-Ga2O3 back barrier

This research demonstrates a p-GaN gate AlGaN/GaN high electron mobility transistor with beta-Ga2O3 back barrier and investigates the electric characteristics of the device. The simulated results show that the threshold voltage of the device will increase with the use of the Ga2O3 back barrier. Moreover, the off-state leakage current level is one order of magnitude lower than the device without back barrier, which can be attributed to the rise of the conduction band diagram in the buffer layer and the decrease of the electron current density released by ionized accept traps. In addition, the impacts of the beta-Ga2O3 back barrier thickness are investigated, and the results show that with increasing Ga2O3 thicknesses, the threshold voltage of the device decreases while the leakage current of the device increases.