Direct heteroepitaxy of β -Ga2O3 on 4H-SiC as a prospective foundation for vertical power devices

We report the successful metal-organic-chemical-vapor deposition-based direct heteroepitaxy of β-Ga2O3 on 4H-SiC (GOSiC) suited for vertical device applications by eliminating the need for interface or buffer layers. We systematically vary the VI/III ratio and growth temperature to study the structural and electrical performance. Structural characterization via transmission electron microscopy, x-ray diffraction, and atomic force microscopy confirms abrupt interfaces, good crystallinity, and low surface roughness. Secondary ion mass spectroscopy analysis demonstrates growth window optimization for low carbon incorporation and suppressed out-diffusion of substrate elements. Ni Schottky barrier diodes fabricated on these films exhibit reverse current characteristics up to 1.18 MV/cm for a 1 mA cm−2 reverse leakage without field management techniques. These results match or surpass those reported for state-of-the-art homoepitaxy on comparable device structures and, to our knowledge, represent the highest breakdown field for β-Ga2O3 heteroepitaxy reported to date. This establishes GOSiC as a promising scalable, thermally managed platform for high-voltage vertical device applications.