Simulation design of high Baliga's figure of merit normally-off P GaN gate AlGaN/GaN heterostructure field effect transistors with junction field plates

Abstract In this paper, we conducted a numerical analysis on novel Normally-off P GaN gate AlGaN/GaN heterostructure field effect transistors with junction field plates (JFP-HFET). The breakdown voltage ( BV) was significantly improved with the introduction of the junction field plate (JFP), which can make a rectangular distribution of the electric field in the GaN channel between the gate and the drain. The highest BV of 1340 V of JFP-HFET could be achieved with the gate to the drain distance L gd  = 6 μm, the length of the P-type region of the JFP L p  = 5.8 μm, the thickness of the JFP T j  = 500 nm, the doping concentration of P-type region of the JFP N p  = 1 × 10 17  cm −3 , and the Al fraction of the AlGaN JFP x Al  = 0.25. The optimum parameters of the JFP-HFET were achieved by considering both the principle of charge balance and the practical fabrication of the III-V devices. The highest Baliga's figure of merit (BFOM) 1.2 GW/cm 2 was obtained under the conditions of L gd  = 6 μm, L p  = 5.8 μm, T j  = 100 nm, N p  = 6 × 10 17  cm −3 , and x Al  = 0.3. C V , turn-on and turn-off processes revealed that the JFP-HFET showed better switching characteristics than that of the HFET with metal field plate.