Effects of oxidation duration on the structural and electrical characteristics of Ho2O3 gate oxide on 4H-SiC substrate

• Main Authors: Odesanya, Kazeem Olabisi, Ahmad, Roslina, Andriyana, Andri, Wong, Yew Hoong
• Format: Article
• Published: Springer 2022
• Subjects: TJ Mechanical engineering and machinery; TK Electrical engineering. Electronics Nuclear engineering
• Online Access: http://eprints.um.edu.my/41982/

This study illustrates the fabrication of Ho2O3 film as gate dielectric using the physical vapour deposition method followed by thermal oxidation on a 4H-SiC substrate. The impacts of oxidation duration on the structural and electrical characteristics of the resulting Ho2O3 layers were studied experimentally at various oxidation periods from 5 to 20 min at a constant temperature of 900 degrees C. The structural characteristics of the Ho2O3 thin film were examined by x-ray diffraction (XRD) and a high-resolution transmission electron microscopy (HRTEM). The crystallinity of the Ho2O3 films was identified by XRD, while crystallite size and microstrain were approximated by a Williamson-Hall (W-H) plot. The electrical properties were investigated by leakage current density-electric breakdown field (J-E), Fowler-Nordheim (F-N) tunnelling, and barrier height. The electrical characterization results have shown an optimized dielectric behaviour of the Ho2O3/SiC obtained at 15 min duration, with the highest breakdown field (7.57 MV/cm) and lowest leakage current density (6.14 x 10(-3) A/cm(2)) recorded. The results of the morphology and thickness of the film have shown that there is no interfacial layer recorded. These findings can be used to provide useful information on the potential of Ho2O3 film to be used as a gate dielectric on 4H-SiC in high-power microelectronics.