Low Turn-On Voltage and High-Power Figure-of-Merit GaN HEMTs With Reverse Blocking Capability

In this article, we demonstrate high-performance reverse blocking GaN high-electron-mobility transistors (HEMTs) with a recessed-drain structure on AlGaN/GaN/AlGaN double heterostructure. By using a low damage recessed-drain structure, the turn-on voltage ( $\textit{V}_{\text{ON}}\text{)}$ as small as 0.35 V is achieved. Furthermore, owing to enhanced carrier confinement, a low subthreshold swing (SS) of 63 mV/decade and a high $\textit{I}_{\text{ON}}$ / $\textit{I}_{\text{OFF}}$ ratio of 10 $^{\text{10}}$ are attained. Meanwhile, the threshold voltage shift is less than 0.15 V under the gate bias stresses of $-$ 20, $-$ 10, and 2 V. The fabricated devices show an excellent gate-bias-induced threshold voltage stability. Furthermore, the proposed devices present a high forward breakdown voltage ( $\textit{V}_{\text{FBR}}\text{)}$ of 2732 V, a high reverse breakdown voltage ( $\textit{V}_{\text{RBR}}\text{)}$ of $-$ 2764 V, and a low reverse leakage current ( $\textit{I}_{\text{R}}\text{)}$ of 0.6 nA/mm at $\textit{V}_{\text{DS}}$ $=$ $-$ 2500 V. The forward and reverse power figures-of-merits (FOMs) of the fabricated devices are 526 and 538 MW/cm $^{\text{2}}$ , respectively, which are the highest among all existing GaN HEMTs with reverse blocking capability.