【Member Papers】Professor Liang Hongwei's Team from Dalian University of Technology on Heteroepitaxial Growth Using MOCVD Method Research on β-Ga₂O₃ Thin Films

      β-Ga₂O₃ is an ultrawide bandgap semiconductor with great potential for solar-blind ultraviolet detection, power devices, and gas sensing. However, the understanding of the surface properties of β-Ga₂O₃ remains insufficient. Here, epitaxial growth of β-Ga₂O₃ films was carried by MOCVD on sapphire substrates. The surface chemical composition, surface one-dimensional defects, and surface morphology of the β-Ga₂O₃ films were discussed and analyzed in detail. By comparing the atomic ratios of O/Ga, surface morphology, and crystalline properties of the films, we attribute the component of O 1s with the binding energy around 531.8 eV to surface lattice O atoms. Moreover, the one-dimensional defects inside the surface layers and the near-interface regions of the films were observed at atomic scale by HRTEM. By comparing the lattice fringes of different facets, the geometric phase uniformity, and the distribution of strain, we found that the crystalline quality of the surface layers is much higher than the near-interface regions.

Paper Link：https://doi.org/10.1016/j.apsusc.2024.159327