Reproducible NiO/Ga2O3 Vertical Rectifiers with Breakdown Voltage >8 kV

Optimized vertical heterojunction rectifiers with a diameter of 100 µm, consisting sputter-deposited p-type NiO forming p–n junction thick (10 µm) Ga2O3 drift layers grown by halide vapor phase epitaxy (HVPE) on (001) Sn-doped (1019 cm−3) β-Ga2O3 substrates, exhibited breakdown voltages >8 kV over large areas (>1 cm2). The key requirements were low layer doping concentrations (<1016 cm3), power during the deposition to avoid interfacial damage at heterointerface and formation guard ring using extension beyond cathode metal contact. Breakdown still occurred contact periphery, suggesting that further optimization edge termination could produce even larger voltages. On-state resistances without substrate thinning <10 mΩ.cm−2, leading figure-of-merits >9 GW.cm−2. devices showed an almost temperature-independent 600 K. These results show remarkable potential NiO/Ga2O3 for performance limits both SiC GaN. important points achieve excellent were: (1) concentration, (2) (3) ring.