Significant improvement of breakdown voltage of Al0.86Ga0.14N Schottky barrier diodes by atomic layer etching

Surface defects in Al-rich AlGaN Schottky barrier diodes (SBDs) contribute to high reverse leakage currents, which limit breakdown voltage—a critical parameter for power applications. In this study, atomic layer etching (ALE) was applied to the Schottky contact area to remove surface defects and native oxide. SBDs without ALE treatment exhibited a breakdown voltage of 308 V, whereas ALE-treated devices achieved a significantly improved breakdown voltage of 1205 V. By reducing interface traps and eliminating native oxide, ALE leads to lower leakage current and a more uniform Schottky barrier. These findings demonstrate that ALE is an effective surface treatment for enhancing the interface quality of III-nitride Schottky barrier diodes, paving the way for high-performance devices and promising advances in other nitride-based power electronics.