【Device Papers】Influence of Ga₂O₃/Al₂O₃ Interface on Characteristics of Ga₂O₃ Capacitors

      Researchers from the National Institute for Material Science have published a dissertation titled "Influence of Ga₂O₃/Al₂O₃ Interface on Characteristics of Ga₂O₃ Capacitors" in ECS Meeting Abstracts.

Abstract

      Various β-Ga₂O₃-based power devices have been widely investigated because β-Ga₂O₃ has a large bandgap of ~4.9 eV and high breakdown electric field of 8 MVcm^-1. It is well understood to be important to reduce the number of electrical defects at the Ga₂O₃/dielectric interface for n-β-Ga₂O₃/dielectric/metal capacitor. However. it was unclear which process in the fabrication of β-Ga₂O₃ capacitors caused these electrical defects. For example, surface cleaning of the β-Ga₂O₃ substrate, an Al₂O₃ film deposition as a dielectric by the atomic layer deposition (ALD) method, and high-temperature annealing (HTA) are considered. On the other hand, for GaN power device, we reported that Ga₂O₃ interfacial layer was generally grown at GaN/SiO₂ interface and affected to electrical properties. And we recently proposed dummy SiO₂ technique (d-SiO₂) to improve the quality of the Ga₂O₃ layer on the GaN surface. In this study, we tried to modify the Ga₂O₃/Al₂O₃ interface using the surface cleaning of β-Ga₂O₃ substrate, HTA at various annealing temperatures in O₂ ambient, and d-SiO₂. We also discuss about influence of Ga₂O₃/Al₂O₃ interface on characteristic including physical and electrical properties for Ga₂O₃ capacitors.

DOI：

https://doi.org/10.1149/MA2025-02361739mtgabs