Investigation of -Ga₂O₃ films and -Ga₂O₃/GaN heterostructures grown by metal organic chemical vapor deposition

In this work, (-2 0 1) beta -Ga2O3 films are grown on GaN substrate by metal organic chemical vapor deposition (MOCVD). It is revealed that the beta -Ga2O3 film grown on GaN possesses superior crystal quality, material homogeneity and surface morphology than the results of common heteroepitaxial beta -Ga2O3 film based on sapphire substrate. Further, the relevance between the crystal quality of epitaxial beta -Ga2O3 film and the beta -Ga2O3/GaN interface behavior is investigated. Transmission electron microscopy result indicates that the interface atom refactoring phenomenon is beneficial to relieve the mismatch strain and improve the crystal quality of subsequent beta -Ga2O3 film. Moreover, the energy band structure of beta -Ga2O3/GaN heterostructure grown by MOCVD is investigated by X-ray photoelectron spectroscopy and a large conduction band offset of 0.89 eV is obtained. The results in this work not only convincingly demonstrate the advantages of beta -Ga2O3 films grown on GaN substrate, but also show the great application potential of MOCVD beta -Ga2O3/GaN heterostructures in microelectronic applications.