High Breakdown Voltage P-GaN Gate HEMTs With Threshold Voltage of 7.1 V
Siheng Chen, Peng Cui, Xin Luo, Liu Wang, Jiacheng Dai, Kaifa Qi, T. Y. Zhang, Handoko Linewih, Zhaojun Lin, Xiangang Xu, Jisheng Han
Abstract
In this study, we proposed an enhanced mode P-GaN/AlGaN/GaN metal-insulator-semiconductor high electron mobility transistors (MIS-HEMTs) by combining thermal oxidation treatment of P-GaN with atomic layer deposition (OTALD) prior to gate metal deposition. Due to the thermal oxidation treatment, a smooth oxide interlayer between P-GaN and Al<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$_{\mathbf {{2}}}$ </tex-math></inline-formula>O<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$_{\mathbf {{3}}}$ </tex-math></inline-formula> is formed. Compared with the device without treatment, the P-GaN gate HEMTs with OTALD present increased threshold voltage significantly from 1.8 V to 7.1 V and improved gate breakdown voltage from 18.9 V to 26.9 V. Additionally, the devices maintained a high on/off current ratio above <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$10^{\mathbf {{8}}}$ </tex-math></inline-formula> and a further improvement in off-state breakdown voltage from 1315 V to 1980 V. The record high threshold voltage and breakdown voltage make this technology promising for widespread application in P-GaN power devices.