1 mm<sup>2</sup>, 3.6 kV, 4.8 A NiO/Ga<sub>2</sub>O<sub>3</sub> Heterojunction Rectifiers
Jian-Sian Li, Chao-Ching Chiang, Xinyi Xia, Hsiao-Hsuan Wan, F. Ren, S. J. Pearton
Abstract
Large area (1 mm 2 ) vertical NiO/ β n-Ga 2 O/n + Ga 2 O 3 heterojunction rectifiers are demonstrated with simultaneous high breakdown voltage and large conducting currents. The devices showed breakdown voltages (V B ) of 3.6 kV for a drift layer doping of 8 × 10 15 cm −3 , with 4.8 A forward current. This performance is higher than the unipolar 1D limit for GaN, showing the promise of β -Ga 2 O 3 for future generations of high-power rectification devices. The breakdown voltage was a strong function of drift region carrier concentration, with V B dropping to 1.76 kV for epi layer doping of 2 × 10 16 cm −3 . The power figure-of-merit, V B 2 /R ON , was 8.64 GW·cm −2 , where R ON is the on-state resistance (1.5 mΩ cm 2 ). The on-off ratio switching from 12 to 0 V was 2.8 × 10 13 , while it was 2 × 10 12 switching from 100 V. The turn-on voltage was 1.8 V. The reverse recovery time was 42 ns, with a reverse recovery current of 34 mA.