NiO/β-(AlxGa1−x)2O3/Ga2O3 heterojunction lateral rectifiers with reverse breakdown voltage >7 kV

Abstract

NiO/β-(AlxGa1−x)2O3/Ga2O3 heterojunction lateral geometry rectifiers with diameter 50–100 μm exhibited maximum reverse breakdown voltages >7 kV, showing the advantage of increasing the bandgap using the β-(AlxGa1−x)2O3 alloy. This Si-doped alloy layer was grown by metal organic chemical vapor deposition with an Al composition of ∼21%. On-state resistances were in the range of 50–2180 Ω cm2, leading to power figures-of-merit up to 0.72 MW cm−2. The forward turn-on voltage was in the range of 2.3–2.5 V, with maximum on/off ratios >700 when switching from 5 V forward to reverse biases up to −100 V. Transmission line measurements showed the specific contact resistance was 0.12 Ω cm2. The breakdown voltage is among the highest reported for any lateral geometry Ga2O3-based rectifier.