Single-crystal single-domain SC2O3 films have been epitaxially grown on Si (1 1 1) using molecular beam epitaxy (MBE) techniques. The SC2O3 films have the bulk bixbyite cubic phase with a very uniform thickness, a structural perfection, and a sharp interface with Si. The thin oxide films exhibit bright, streaky, and reconstructed RHEED patterns. The high-intensity oscillation in the reflectivity, the strong Pendollusung fringes around the SC2O3 (2 2 2) diffraction peak, and their narrow rocking curves are observed using the high-resolution X-ray diffraction (XRD). The (1 1 1) axis of the oxide films is parallel to the (1 1 1) axis of the Si substrate. The cone scans of the Sc2O3 {440} and Si {220} diffraction peaks about the surface normal find a 60° symmetry rotation of the film with the respect to the substrate. The Sc2O3 films exhibit low electrical leakage currents and a breakdown field of more than 5 MV/cm. © 2005 Elsevier B.V. All rights reserved.