Dependence of Y ₂O ₃ film growth on the state of the Si surface

Y ₂O ₃ films were grown on Si substrates with various surface conditions by using ionized cluster beam deposition. The interface and the surface characteristics was investigated by reflection high energy electron diffraction, atomic force microscopy, and X-ray photoelectron spectroscopy. The dependence of the crystallinities of the films on the surface conditions was investigated using X-ray diffraction. The investigation showed that control of the suicide layer played a crucial role in the growth of Y ₂O ₃ film during the initial stage of growth. The Y ₂O ₃ film grown on a suicide layer formed on a clean Si surface was a polycrystal with a monoclinic structure. However, the film grown on a suicide layer formed on a SiO ₂-terminated surface turned out to be a single crystalline Y ₂O ₃ with a cubic structure. A high-quality film in terms of crystallinity and stochiometry was obtained when the growth of the suicide layer was controlled by a SiO ₂ layer which had been formed by using a wet chemical treatment.