Epitaxial Y₂O₃ film growth on an oxidized Si surface

The effects of the Si surface state on epitaxial growth of Y₂O₃ layers were investigated by various measurement methods. The characterization using X-ray diffraction (XRD), Rutherford backscattering spectroscopy (RBS) and high-resolution transmission electron microscopy (HRTEM) shows excellent film crystallinity when grown on an oxidized Si surface. The crystalline structure of the film was influenced by the interfacial mosaic structure, which depended on whether the Si surface contained adsorbed O or not. The thin SiO₂ layer of approximately 1.5 nm, provided favorable interfacial reaction sites for the nucleation of Y₂O₃, and still maintained the structural registry with the underlying Si substrate. In particular, the reaction between the Y and SiO₂ layer resulted in coherent finite growth, whereas the direct interaction between Y and Si was hindered by the nucleation of Y₂O₃. The high-quality epitaxial layer with the minimum channel yield (χ_min), lower than 3%, could be grown on the oxidized Si surface.