GaN Lateral Schottky Diodes with High Baliga's Figure-of-Merit Utilizing Self-Terminated, Low Damage Anode Recessing Technology

AlGaN/GaN lateral diodes on silicon are considered very promising for next generation power conversion systems owing to the excellent material properties. Typically, the anode recess is a frequently-used and effective technology in reducing the SBD's VON and $\mathrm{R}_{\mathrm{ON},\mathrm{SP}}$ [1]. However, the rough surface morphology and poor recess depth control in common dry etching are two critical issues that would lead to an increased leakage current and premature breakdown [2]. In this report, we employ a LPCVD $\mathrm{Si}_{3}\mathrm{N}_{4}$ compatible self-terminated, and plasma-free recess technique in an AlGaN/GaN double channel anode-recessed SBD. The anode region is prevented from plasma bombardment and the recess could stop precisely at the upper heterojunction interface with a smooth surface morphology. The SBD with a $15\ \mu \mathrm{m}\ L_{\mathrm{AC}}$ exhibits a low $\mathrm{R}_{\mathrm{ON},\mathrm{SP}}$ of $1.32\ \mathrm{m}\Omega\cdot \mathrm{cm}^{2}$, a remarkable $V_{\mathrm{ON}}$ uniformity and a leakage current of $\sim 0.2\ \mu \mathrm{A}/\mathrm{mm}$ at −300 V. Moreover, with the assistance of high quality LPCVD $\mathrm{Si}_{3}\mathrm{N}_{4}$, a 1.2kV breakdown voltage and a high Baliga' $\mathrm{s}$ figure-of-merit of $1.1\mathrm{GW}/\mathrm{cm}^{2}$ are ultimately achieved in the same device.