Topic: Fabrication and characterization of Ga₂O₃-based rectifying diodes for high-voltage applications
Supervisor: : Ing. Filip Gucmann, PhD. (Department of III-V Semiconductors)
Co-advisor: RNDr. Dagmar Gregušová, DrSc.
Description: Gallium oxide (Ga₂O₃) is a novel ultra-wide-bandgap semiconductor material with a bandgap energy (Eg) of approximately 5 eV and a theoretical critical breakdown field (Ecr) exceeding 8 MV/cm, which makes it highly suitable for high-power and high-voltage rectifying and switching applications. Devices based on monoclinic β-Ga₂O₃ have the potential to significantly extend the capabilities of currently established semiconductors such as GaN and SiC and to enable reliable operation at voltages >6 kV, where suitable alternative is currently unavailable. Such devices are expected to find applications in high-efficiency power conversion systems, for example in fast battery chargers for electromobility, renewable energy sources (solar, wind), as well as in the defence sector.
This work will focus on the optimization of fabrication technology for Schottky-barrier diodes in vertical and semi-vertical configurations, as well as on a detailed study of transport mechanisms and degradation processes in these devices. The Ga₂O₃ semiconductor material will be grown by MOCVD at the Institute of Electrical Engineering of the Slovak Academy of Sciences (IEE SAS), v. v. i., on various substrates (Ga₂O₃, SiC, Si, sapphire), enabling the investigation of self-heating effects. The research will also include an investigation of the impact of various edge termination and protection structures (field plates, guard rings, etc.) on the reverse breakdown voltage of the diodes. The devices will be fabricated using advanced photolithographic processes and other technologies available at IEE SAS, in collaboration with the Taiwan Industrial Technology Research Institute (ITRI).