High surface quality heteroepitaxy α-Ga₂O₃ film on sapphire by mist-CVD technique

Abstract An ultra-flat heteroepitaxy α-Ga2O3 thin film, paved a glory future for device fabrication, was successfully obtained on a c-plane sapphire substrate through the employment of the mist chemical vapor deposition technique. Atomic force microscopy measurements revealed an root mean square (RMS) roughness value of 0.309 nm when the carrier gas flow rate was set at 1500 sccm. Furthermore, the full-width at half maximum of the rocking curve was determined to be 43.2 arcsec, indicating a high level of crystallinity in the heteroepitaxy film. The growth rate was calculated as 13.22 nm min−1 through the use of cross-section scanning electron microscope measurements. Additionally, the bandgap of the transparent film was determined to be 5.10 eV through transmittance spectra analysis. The high quality, wide bandgap heteroepitaxy α-Ga2O3 thin film described in this study represents a significant step forward in the preparation of high power and optoelectronic devices.