Microstructure of epitaxial Er₂O₃ thin film on oxidized Si (111) substrate

Er₂O₃ thin films are grown on oxidized Si (111) substrates by molecular beam epitaxy. The sample grown under optimized condition is characterized in its microstructure, surface morphology and thickness using grazing incidence x-ray diffraction (GIXRD), atomic force morphology and x-ray reflectivity. GIXRD measurements reveal that the Er₂O₃ thin film is a mosaic of single-crystal domains. The interplanar spacing d in-plane residual strain tensor ε_∥ and the strain relaxation degree ξ are calculated. The Poisson ratio μ obtained by conventional x-ray diffraction is in good agreement with that of the bulk Er ₂O₃. In-plane strains in three sets of planes, i.e. (440), (404), and (044), are isotropic.