β-Ga2O3 based semiconductor devices are expected to have significantly improved high-power and high-temperature performance due to its ultra-wide bandgap of close to 5 eV. However, the high-temperature operation of these ultra-wide-bandgap devices is usually limited by the relatively low 1-2 eV built-in potential at the Schottky barrier with most high-work-function metals. Here, we report heterojunction p-NiO/n-β-Ga2O3 diodes fabrication and optimization for high-temperature device applications, demonstrating a current rectification ratio of more than 106 at 410{\deg}C. The NiO heterojunction diode can achieve higher turn-on voltage and lower reverse leakage current compared to the Ni-based Schottky diode fabricated on the same single crystal β-Ga2O3 substrate, despite charge transport dominated by interfacial recombination. Electrical characterization and device modeling show that these advantages are due to a higher built-in potential and additional band offset. These results suggest that heterojunction p-n diodes based on β-Ga2O3 can significantly improve high-temperature electronic device and sensor performance.
Cite
@article{arxiv.2204.00112,
title = {Gallium Oxide Heterojunction Diodes for Improved High-Temperature Performance},
author = {Shahadat H. Sohel and Ramchandra Kotecha and Imran S Khan and Karen N. Heinselman and Sreekant Narumanchi and M Brooks Tellekamp and Andriy Zakutayev},
journal= {arXiv preprint arXiv:2204.00112},
year = {2022}
}