Low leakage and high blocking voltage GaN-on-GaN Schottky diode by TMAH surface treatment

Abstract

In this study, the impact of surface treatment by TMAH and HF on the electrical characteristics of GaN-on-GaN Schottky diodes is examined through I–V and C–V characterizations. A TMAH surface treatment leads to an improvement in the reverse characteristics of the devices and improvement in breakdown voltage (BV) by almost 200 V compared to HF treatment. Additional XPS characterizations reveal a reduction in both O and C concentration from the surface due to TMAH treatment. When combined with proper edge termination techniques, this approach can help achieve breakdown voltages that are closer to the theoretical limits.

Keywords

• Vertical GaN
• Schottky diode
• Surface preparation
• Electrical characterizations