Electric Field Management and Sidewall Leakage Current Suppression of RESURF-mesa for High-Performance Ga 2 O 3 Power Devices

作者：Jiangbin Wan, Hengyu Wang, Haoyuan Cheng, Ce Wang, Chi Zhang, Kuang Sheng · 发表于：IEEE Transactions on Electron Devices · 年份：2025 · DOI：10.1109/ted.2025.3594329 · 被引用次数：8 · 研究领域：Ga2O3 and related materials、Semiconductor materials and devices、ZnO doping and properties

This work demonstrates high-performance vertical$\boldsymbol{\beta}$-Ga$\boldsymbol{_\text{2}}$O$\boldsymbol{_\text{3}}$rectifiers featuring a reduced-surface-field mesa (RESURF-mesa) structure. This RESURF-mesa design employs nonself-aligned etching to form a 5-$\boldsymbol{\mu}$m deep mesa, utilizing a 5-μm-thick SiO$\boldsymbol{_\text{2}}$layer and 120-nm p-type nickel oxide (NiO) to encapsulate the sidewalls with an argon-to-oxygen flux ratio of 20:1. Technology computer-aided design (TCAD) simulations confirm a reduced surface electric field (E-field) with an optimized NiO thickness. Consequently, the RESURF-mesa Schottky barrier diode (SBD) with 120-nm NiO exhibits a breakdown voltage (BV) of 2600 V, while the RESURF-mesa heterojunction diode (HJD) sustains a reverse voltage exceeding 3000 V due to the stronger heterointerface. The specific ON-resistance ($\boldsymbol{\mathit{\textit{R}}}\boldsymbol{_{\textit{ON},\textit{sp}}}$) of both devices is 4.1 m$\boldsymbol{\Omega}\cdot$cm$\boldsymbol{^\text{2}}$, yielding the power figure of merit (PFOM) of 1.6 GW/cm$\boldsymbol{^\text{2}}$for RESURF-mesa SBD and 2.2 GW/cm$\boldsymbol{^\text{2}}$for RESURF-mesa HJD. The performance of both rectifiers is among the highest in reported multikilovolts Ga$\boldsymbol{_\text{2}}$O$\boldsymbol{_\text{3}}$SBDs and HJDs. Additionally, we have investigated the origin of sidewall leakage current and developed methods to suppress it, which is also effective at high temperatures. These find...