A novel AlGaN/GaN Schottky barrier diode with partial p-AlGaN cap layer and recessed dual-metal anode for high breakdown and low turn-on voltage

Abstract

A novel AlGaN/GaN Schottky barrier diode with partial p-AlGaN cap layer and recessed dual-metal anode is proposed and investigated by TCAD simulation in this work. By utilizing this structure, the device can achieve both enhanced reverse blocking capacity and superior forward performance. The operating mechanism of the partial p-AlGaN cap layer is analyzed. Carriers underneath the partial cap layer are depleted, and the electric field is redistributed, leading to a lower reverse leakage current and a higher breakdown voltage. Additionally, the recessed dual-metal anode allows the device to turn on at a low forward bias. The effect of the length and thickness of partial p-AlGaN cap layer on the reverse and forward performance has been further investigated, respectively. The optimized device shows excellent performance with a breakdown voltage of 2461 V, a turn-on voltage of 0.43 V, and the highest Baliga’s figure of Merit of 1738 MW cm−2. The fabrication issues of the proposed device have also been presented.