Ultrathin barrier AlGaN/GaN hybrid‐anode‐diode with MOCVD in‐situ Si 3 N 4 ‐cap and LPCVD‐Si 3 N 4 bilayer passivation stack for dynamic characteristic improvement

Abstract

A novel ultrathin barrier AlGaN/GaN hybrid-anode-diode (UTB-HAD) with in-situ Si 3 N 4 -cap passivation is experimentally demonstrated. The forward turn-on voltage ( V on ) of the UTB-HAD is determined by the intrinsic threshold voltage of the two-dimension electron gas (2DEG) channel, which can be precisely controlled by tailoring the as-grown AlGaN-barrier thickness. The typical V on as low as 0.48 V is obtained by using the UTB AlGaN/GaN with a barrier thickness of 4.9 nm. The MOCVD has grown in-situ Si 3 N 4 -cap and the LPCVD-Si 3 N 4 bilayer passivation stack is developed to effectively restore the 2DEG in the UTB AlGaN/GaN heterostructure and simultaneously improve the dynamic characteristics of the diode. The UTB-HAD and the novel passivation scheme are of great potential for power applications.