[12p-N305-1~14] 13.7 Compound and power devices, process technology and characterization

[12p-N305-4] Breakdown characteristics of p-GaN/AlGaN/GaN diode with controlled charge concentration by changing Mg-doped GaN thickness

〇(M2)Soichiro Kawata¹, Yuwei Zhang¹, Iwata Naotaka¹ (1.Toyota Tech. Inst.)

Keywords:gallium nitride

The p-GaN/AlGaN/GaN heterostructure superjunction can achieve low on-resistance and high breakdown-voltage. For high breakdown-voltage, it is necessary to balance positive and negative charge concentrations. The charge concentrations were controlled by changing the thickness of p-GaN layer. For the more than 50nm thick p-GaN layer, there is no correlation between the drift-region-lengths and the breakdown-voltages. For the less than 40nm thick p-GaN layer, the breakdown-voltages improved as the drift-region-lengths increased. It is because the charge concentrations are balanced by decrease in the acceptors, then the electric field gets uniform.