Dynamic Switching of 1.9 A/1.76 kV Forward Current NiO/ β-Ga₂O₃Rectifiers

The switching performance of unpackaged vertical geometry NiO/β-Ga2O3 rectifiers with a reverse breakdown voltage of 1.76 kV (0.1 cm diameter, 7.85 × 10-3 cm2 area) and an absolute forward current of 1.9 A fabricated on 20 μm thick epitaxial β-Ga2O3 drift layers and a double layer of NiO to optimize breakdown and contact resistance was measured with an inductive load test circuit. The Baliga figure-of-merit of the devices was 261 MW.cm-2, with differential on-state resistance of 11.86 mω.cm2. The recovery characteristics for these rectifiers switching from forward current of 1 A to reverse off-state voltage of -550 V showed a measurement-parasitic-limited recovery time (trr) of 101 ns, with a peak current value of 1.4 A for switching from 640 V. The reverse recovery time was limited by extrinsic parasitic and thus does not represent the intrinsic device characteristics. There was no significant dependence of trr on switching voltage or forward current.