Instability of parasitic capacitance in T-shape-gate enhancement-mode AlGaN/GaN MIS-HEMTs
Lan Bi, Yixu Yao, Qimeng Jiang, Sen Huang, Xinhua Wang, Hao Jin, Xinyue Dai, Zhengyuan Xu, Jie Fan, Haibo Yin, Ke Wei, Xinyu Liu
Abstract
Abstract Parasitic capacitances associated with overhangs of the T-shape-gate enhancement-mode (E-mode) GaN-based power device, were investigated by frequency/voltage-dependent capacitance–voltage and inductive-load switching measurements. The overhang capacitances induce a pinch-off voltage distinguished from that of the E-mode channel capacitance in the gate capacitance and the gate–drain capacitance characteristic curves. Frequency- and voltage-dependent tests confirm the instability caused by the trapping of interface/bulk states in the LPCVD-SiN x passivation dielectric. Circuit-level double pulse measurement also reveals its impact on switching transition for power switching applications.