An energy-band modulated p-GaN/InGaN/AlN p-channel MESFET with high <i>ION</i>/<i>IOFF</i> ratio and steep subthreshold swing
Huake Su, Tao Zhang, Shengrui Xu, Hongchang Tao, Yuan Gao, Xu Liu, Lei Xie, Xiang Peng, K. Y. Cheng, Yue Hao, Jincheng Zhang
Abstract
In this work, we report on the high-performance p-GaN/InGaN/AlN multi-heterostructure p-channel metal–semiconductor field effect transistors (MESFETs) with energy-band modulated quantum well-like InGaN channel and low work function metal tungsten (W) as the gate material. A negative threshold voltage (VTH) of −0.35 V is achieved by precisely controlling the self-aligned etching depth at the active region. Benefiting from the enhanced hole confinement, the ION/IOFF ratio and subthreshold swing of the fabricated-channel MESFET are extracted to be 1.2 × 107 and 66 mV/dec, respectively, at room temperature. The idealized Schottky interface with TMAH and post-gate-annealing treatment shows an ultra-low voltage hysteresis of 0.08 V extracted at subthreshold area in the dual-sweep transfer curves.