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

摘要

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 VONand$mathrm{R}_{mathrm{ON},mathrm{SP}}$[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$1.32 mathrm{m}Omegacdot mathrm{cm}^{2}$, 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$1.1mathrm{GW}/mathrm{cm}^{2}$are ultimately achieved in the same device.