Influence of dry-etching damage on the electrical properties of an AlGaN/GaN Schottky barrier diode with recessed anode

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.