Fluorine-Implanted Termination for Vertical GaN Schottky Rectifier With High Blocking Voltage and Low Forward Voltage Drop

Abstract

In this letter, fluorine-implanted termination (FIT) has been demonstrated in vertical GaN-on-GaN Schottky barrier diodes (SBDs). Owing to the unique feature of F ions that can become negative fixed charges in GaN, the electric field crowding at the junction edge can be mitigated and the breakdown voltage ( BV ) of the vertical GaN SBDs can be effectively enhanced. For SBDs, it is challenging to simultaneously achieve both high BV and low forward voltage drop ( ${V}_{{F}}$ ). Thanks to the effective leakage suppression by FIT, a high BV of ~800 V is realized in an FIT-SBD even with a low ${V}_{{F}}$ value of 0.85 V (at 100 A/cm2). By incorporating an AlGaN tunneling-enhancement layer, the FIT-SBD can achieve further improved BV of ~1020 V and ${V}_{{F}}$ of 0.83 V. Fast reverse recovery performance has also been realized in the FIT-SBDs.