A Novel p-GaN Gate HEMT with p-Type Doping Concentration Graded Termination

In this paper, a novel p-GaN gate HEMT with p-type doping concentration graded termination (PGT-HEMT) is proposed and simulated. The proposed structure improves the breakdown voltage from 622 V to 1585 V compared to conventional p-GaN gate HEMT. Further, the mechanism of breakdown voltage enhancement is investigated and the electric field distribution is simulated. The p-type termination in the PGT-HEMT extends the depletion region in the channel below the gate and introduces new peaks in the electric field. This effectively disperses the main peak electric field in the channel and gives the device a higher ability to withstand voltage. And the breakdown properties of PGT-HEMT with different lengths and different concentration gradients of p-type terminals were investigated. In addition, the p-type termination boosts the breakdown voltage while improving the RON of device, which demonstrates its great potential for power electronics applications.