Room-temperature epitaxial growth of CeO2(001) thin films on Si(001) substrates by electron beam evaporation

Epitaxial growth of CeO2(001) thin films on Si(001) substrates was achieved by electron beam evaporation. Reflection high-energy electron diffraction and cross-sectional high-resolution transmission electron microscopy established the formation of an epitaxial CeO2(001)/Si(001) structure with a cube-on-cube configuration. The epitaxial structure had to be formed at a temperature below 200 °C with a Si(001)-2×1, 1×2 reconstructed surface, and it could be formed even at room temperature. In order to improve the crystallinity, homoepitaxial growth conditions at a higher temperature with a high oxygen flow rate were also investigated. Homoepitaxy of ceria grown on a 5-nm-thick initial layer was demonstrated by θ/2θ-scan and φ-scan of x-ray diffraction.