Field management in NiOx/β-Ga2O3 merged-PIN Schottky diodes: simulation studies and experimental validation

In recent years, p-type NiOx has emerged as a promising alternative to realize kilovolt-class beta-Ga2O3-based PN junction diodes. However, only a handful of studies could realize beta-Ga2O3-based unipolar diodes using NiOx as a guard ring or floating rings. In this work, we investigate the device design of NiOx/beta-Ga2O3 unipolar diodes using the technology computer aided design simulations and experimental validations. We show that a systematic electric field management approach can potentially lead to NiOx/beta-Ga2O3 heterojunction unipolar diode and offer enhanced breakdown characteristics without a severe compromise in the ON-state resistance. Accordingly, the NiOx/beta-Ga2O3 heterojunction diode in the merged-PIN Schottky configuration is shown to outperform the regular Schottky diode or junction barrier Schottky diode counterpart. The analysis performed in this work is believed to be valuable in the device design of beta-Ga2O3-based unipolar diodes that use a different p-type semiconductor candidate as guard rings and floating rings.