Influence of dry-etching damage on the electrical properties of an AlGaN/GaN Schottky barrier diode with recessed anode**Project supported by the National Natural Science Foundation of China (Grant Nos. 51177175 and 61274039), the National Basic Research Program of China (Grant Nos. 2010CB923200 and 2011CB301903), the Ph. D. Programs Foundation of Ministry of Education of China (Grant No. 20110171110021), the International Science

Abstract

The influences of dry-etching damage on the electrical properties of an AlGaN/GaN Schottky barrier diode with ICP-recessed anode was investigated for the first time. It was found that the turn-on voltage is decreased with the increase of dry-etching power. Furthermore, the leakage currents in the reverse bias region above pinch-off voltage rise as radio frequency (RF) power increases, while below pinch-off voltage, leakage currents tend to be independent of RF power. Based on detailed current–voltage–temperature (I–V–T) measurements, the barrier height of thermionic-field emission (TFE) from GaN is lowered as RF power increases, which results in early conduction. The increase of leakage current can be explained by Frenkel–Poole (FP) emission that higher dry-etching damage in the sidewall leads to the higher tunneling current, while below pinch-off voltage, the leakage is only related to the AlGaN surface, which is independent of RF power.