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 β-Ga2O3 based PN junction diodes. However, only a handful number of studies have been performed to realize β-Ga2O3-based unipolar diodes using NiOx as guard-ring or floating rings. In this work, we investigated the device-design of NiOx/β-Ga2O3 unipolar diodes using Technology Computer Aided Design (TCAD) simulations and experimental validations. We show that a systematic electric field management approach can potentially lead to NiOx/β-Ga2O3 heterojunction unipolar diode offering improved breakdown characteristics without a serious compromise in ON-state resistance. Accordingly, NiOx/β-Ga2O3 heterojunction diode in 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 thought to be valuable in device-design of β-Ga2O3-based unipolar diodes that use a different p-type semiconductor candidate as guard ring and floating rings.