Design and fabrication of field-plated normally off <b> <i>β</i> </b>-Ga2O3 MOSFET with laminated-ferroelectric charge storage gate for high power application
Zhaoqing Feng, Yuncong Cai, Zhe Li, Zhuangzhuang Hu, Yanni Zhang, Xing Lü, Xuanwu Kang, Jing Ning, Chunfu Zhang, Qian Feng, Jincheng Zhang, Hong Zhou, Yue Hao
Abstract
In this work, an enhancement-mode (E-mode) β-Ga2O3 metal-oxide-semiconductor field-effect transistor (MOSFET) has been achieved by incorporating a laminated-ferroelectric charge storage gate (L-FeG) structure [Al2O3/HfO2/Al2O3/Hf0.5Zr0.5O2 (HZO) of 10/5/2/16 nm]. The band diagram between L-FeG dielectrics (Al2O3, HfO2, and HZO) and β-Ga2O3 was determined by x-ray photoelectron spectroscopy. After applying a gate pulse with an intensity of +18 V and width of 1 ms, the saturation current of the E-mode device was measured to be 23.2 mA/mm, which shows a negligible current reduction compared to that of 22.1 mA/mm in a depletion- (D-) mode device. In addition, the threshold voltage (VTH) is only shifted by 2.76% and 2.18%, respectively, after applying the gate stress and gate-drain stress of 15 V for 104 s. Meanwhile, a high breakdown voltage of 2142 V and specific on-resistance (RON,sp) of 23.84 mΩ·cm2 were also achieved, which correspond to a state-of-art high power figure of merit of 192.5 MW/cm2, showing the great potential of combing the ferroelectric gate stack and lateral Ga2O3 MOSFET as next generation power devices.