LOW-TEMPERATURE EPITAXIAL-GROWTH OF CERIUM DIOXIDE LAYERS ON (111) SILICON SUBSTRATES

The temperature dependence of the epitaxial growth of cerium dioxide (CeO2) layers on (111) silicon substrates was studied using ultra-high-vacuum evaporation, varying the substrate temperature in the range between 150 and 900-degrees-C. Characterization using Rutherford backscattering spectrometry and reflection high-energy electron diffraction proved that a CeO2 layer on (111) silicon has considerably good crystalline quality in the range between 200 and 850-degrees-C. It is clarified that the epitaxy can be attained even at surprisingly low temperatures (less than 200-degrees-C). A substrate temperature above 850-degrees-C leads to rather poor crystallinity due to an exponential increase of residual gas pressure. Refractive indices of the epitaxial layers were measured by ellipsometry to be in the range of 2.19-2.79.