Improving the Performance of Deep Recessed Anode AlGaN/GaN Schottky Barrier Diode by Post Etching Treatment

Abstract

Herein, fluorine (F) plasma and HCl solution treatments are used as post etching treatment to improve the performance of recessed anode AlGaN/GaN Schottky barrier diodes (SBDs). To avoid the deterioration in the forward characteristics caused by F‐plasma treatment, the deep recessed anode structure is designed. Simulation results show that when the recessed depth exceeds 60 nm, the forward current is not reduced after the F‐plasma treatment. The recessed depth of 70 nm is chosen in the experiment. After the post etching treatment, the on‐resistance (RON) and forward voltage (VF) are reduced by 0.4 Ω mm and 0.4 V, respectively. The improvement of forward characteristic is attributed to the change of electron transport paths, which is due to the increase in barrier height and width at anode sidewall caused by F ions. Moreover, the reverse current (IREV) is suppressed by two orders of magnitude. It can be explained by the dispersion of electric field peaks by F‐plasma treatment and repair of etching damage after HCl treatment.