Effects of NiO Doping and Trench Wall Tilt on Ga2O3 PiN Diodes Performance

Gallium Oxide (Ga2O3) is a promising material for next-generation power semiconductors due to its wide bandgap (∼4.9 eV), high Baliga's figure of merit (FOM) (3444 W/cmK), and high breakdown field (Ec, 8 MV/cm). To achieve high blocking and low leakage current, research has been conducted on PN heterojunctions and bevel structures. In this paper, we performed simulations using Sentaurus TCAD to investigate the impact of NiO doping concentration and NiO's trench tilt angle on the electrical characteristics of NiO/Ga2O3 PiN diodes with trench NiO. As the NiO doping concentration increased, the resistance decreased from 21.5 to 7.5 mΩcm2, and we observed the expansion of depletion from NiO to the NiO/Ga2O3 interface. Furthermore, we confirmed a reduction in resistance and a change in breakdown voltage with an increase in NiO trench tilt. By understanding the optimal angle to mitigate the concentration of high electric fields in the edge region, we anticipate the fabrication of stable Ga2O3 PiN diodes.