Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5465998 | Thin Solid Films | 2017 | 7 Pages |
Abstract
Thin films of cerium dioxide (CeO2) were deposited by atomic layer deposition (ALD) at 250 °C on both Si and titanium nitride (TiN) substrates. The ALD growth produces CeO2 films with polycrystalline cubic phase on both substrates. However, the films show a preferential orientation along ã200ã crystallographic direction for CeO2/Si or ã111ã for CeO2/TiN, as revealed by X-ray diffraction. Additionally, CeO2 films differ in the interface roughness depending on the substrate. Furthermore, the relative concentration of Ce3 + is 22.0% in CeO2/Si and around 18% in CeO2/TiN, as obtained by X-ray photoelectron spectroscopy (XPS). Such values indicate a ~ 10% off-stoichiometry and are indicative of the presence of oxygen vacancies in the films. Nonetheless, CeO2 bandgap energy and refractive index at 550 nm are 3.54 ± 0.63 eV and 2.3 for CeO2/Si, and 3.63 ± 0.18 eV and 2.4 for CeO2/TiN, respectively. Our results extend the knowledge on the structural and chemical properties of ALD-deposited CeO2 either on Si or TiN substrates, underlying films differences and similarities, thus contributing to boost the use of CeO2 through ALD deposition as foreseen in a wide number of applications.
Keywords
Related Topics
Physical Sciences and Engineering
Materials Science
Nanotechnology
Authors
S. Vangelista, R. Piagge, S. Ek, T. Sarnet, G. Ghidini, C. Martella, A. Lamperti,