Gate Current Transport in Enhancement-Mode <i>p</i>-<i>n</i> Junction/AlGaN/GaN (PNJ) HEMT
Mengyuan Hua, Chengcai Wang, Junting Chen, Junlei Zhao, Song Yang, Li Zhang, Zheyang Zheng, Jin Wei, Kevin J. Chen
Abstract
In this work, we study the gate leakage mechanisms of E-mode p- n junction/AlGaN/GaN (PNJ) high electron mobility transistors (HEMTs), which have been shown to deliver low gate leakage and wide safe operating gate-bias range. The intrinsic gate leakage through the PNJ-gate was found to be limited by the transport of holes through the p-GaN layer, which occurs via Poole-Frenkel emission and phonon-assisted tunneling in low and high gate bias region, respectively. In addition, lateral leakage current and the role of variable hopping process (VRH) are also discussed. Gate leakage current models based on the revealed mechanisms can quantitatively reproduce the gate-leakage behavior in the entire relevant range of gate biases and temperatures.