Effects of different growth conditions on epitaxial growth of (001) Ga₂O₃ films by MOCVD

The β-Ga₂O₃ epitaxial thin films were grown on (001) β-Ga₂O₃ substrates using metalorganic chemical vapor deposition (MOCVD), and the effects of key growth parameters — including temperature, pressure, and oxygen-to-gallium ratio (O₂/Ga) — on the crystalline quality, surface morphology, and electrical properties of the films were systematically investigated. The results show that while variations in these parameters did not alter the (001) preferential orientation of the β-Ga₂O₃ films, they significantly influenced other properties. By optimizing the growth parameters, films with a surface roughness as low as 1.5 nm and the full width at half maximum (FWHM) of 33.7 arcsec were achieved. X-ray photoelectron spectroscopy (XPS) analysis showed that the oxygen vacancy concentration was significantly reduced under the optimized O₂/Ga ratio of 820. Schottky barrier diodes (SBDs) were fabricated from three different β-Ga₂O₃ films grown under distinct O₂/Ga ratios. The SBD fabricated under the optimized O₂/Ga ratio of 820, exhibits a low turn-on voltage of 0.5 V, low on-resistance of 0.022 mΩ⋅cm², and a high forward current density of 678.16 A/cm² at 3 V. These results provide essential material and theoretical foundations for the development of β-Ga₂O₃ based high-power electronic devices.