@misc{GertigMoralesHenkeletal., author = {Gertig, Max and Morales, Carlos and Henkel, Karsten and Flege, Jan Ingo}, title = {In situ X-ray photoelectron spectroscopy study of atomic layer deposited ceria on SiO2: substrate influence on the reaction mechanism during the early stages of growth}, series = {Verhandlungen der DPG}, journal = {Verhandlungen der DPG}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, abstract = {Atomic layer deposition (ALD) is known to produce amorphous and defect-rich films in a layer-by-layer fashion, which can potentially give rise to unexpected material properties. In particular, ultrathin films (few monolayers) will show the highest complexity, as the substrate-material interaction will play a major role during deposition. Therefore, it is crucial to understand the early stages of growth of the ALD process to control and potentially tailor this interfacial interaction. Applying a surface science approach combined with complementary ex-situ characterization, we have studied by in-situ X-ray photoelectron spectroscopy (XPS) the early stages of ceria (CeOx) growth on SiO2 substrates deposited by thermal-ALD using Ce(thd)4/O3. Interestingly, an initial mixture of Ce3+ and Ce4+ was observed, although only Ce4+ may be expected considering the used precursor and oxidant. This fact, together with a deviation from the ideal layer-by-layer growth and a higher growth rate during the first cycles, indicates a significant influence of the substrate of the ALD reaction mechanism as well as a correlation between morphology and ceria oxidation state.}, language = {en} }