2 kV monolithic bidirectional Al 0.61 Ga 0.39 N-channel HEMT-on-sapphire substrate

Al 0.61 Ga 0.39 N-channel monolithic bidirectional HEMTs were demonstrated for the first time on sapphire substrate, achieving a breakdown voltage of 2 kV with a specific on-resistance of 17.53 m Ω ⋅ cm 2 . A high-Al-composition (61%) AlGaN channel was utilized to enhance the breakdown voltage and breakdown field. For devices with gate-to-gate spacings of 3, 8, and 12 μm, the breakdown fields were 2.42 MV cm −1 , 1.75 MV cm −1 , and 1.66 MV cm −1 , respectively. The corresponding on-resistances were 7.63, 12.59, and 17.53 m Ω ⋅ cm 2 , respectively. One gate-connected field plate on each side was incorporated for electric-field management. Bidirectional output characteristics, transfer curves, off-state leakage, and breakdown characteristics were reported.