Abstract
Sc2O3 films had been found to be epitaxially grown on Si (111) substrate with different thickness. With electron beam evaporated from a high-purity Sc2O3 source in UHV (a molecular beam epitaxy (MBE) approach), we got good crystallinity Sc2O3 film on silicon substrate. The in-situ reflection high energy electron diffraction (RHEED) was used to monitor the surface of the sample during the growth process. Structural and morphological studies were examined bysingle x-ray diffraction(XRD), and high-resolution transmission electron microscopy(HRTEM). The film thickness has been studied using low-angle x-ray diffraction (XRR) and cross-sectional TEM.The Sc2O3 films grown in our MBE system have a cubic phase with a very uniform thickness and a highly structural perfection, even for films as thin as 1.5 nm. Moreover,without capping amorphous silicon to protect the Sc2O3 film, there has no interfacial layer exist in the interface. The film normal was found to be <111>, which is well aligned with the Si substrate normal. From the phi scan the in plane relation was rotated by 60 degree, and was proved by electron diffraction. To describe the periodical dislocation in the interface, we quoted Bollmann O-lattice theory, and estimated of the spacing between dislocations. We are surprised with large lattice mismatch (up to 9.3%) Sc2O3 still can form one domain crystalline film.