EPITAXIAL-GROWTH OF CEO2 FILMS ON SI(111) BY SPUTTERING

CeO2 films were epitaxially grown on Si(111) substrates by reactive sp uttering following the single-crystal CeO2 seed layer formation by oxy gen-reactive solid-phase epitaxy. Formation of metallic Ce layers and oxidation of the layers prior to reactive sputtering was found to be t he key process for epitaxial growth of CeO2 on Si substrates. An Auger electron spectroscopy depth profiling analysis showed that the Ce-Si interlayer was formed after the Ce metal deposition. Reflection high-e nergy electron diffraction and transmission electron microscopy proved that epitaxial CeO2 films were grown by reactive sputtering on the se ed layers formed by oxidation of Ce metal layers with thickness of 5 t o 10 nm. Crystalline quality of the films depended on the sputtering c onditions, especially on total sputtering pressure and oxygen concentr ation. The optimization of the conditions for seed layer formation by oxygen-reactive solid-phase epitaxy and reactive sputtering was an imp ortant factor for improving the crystalline quality of epitaxially gro wn CeO2 film.