Nucleation and growth of nanophasic CeO2 thin films by plasma- enhanced CVD

Nanophasic CeO2-based thin films were grown at low temperatures on SiO2 and Si(100) by plasma-enhanced (PE) CVD from a CeIV beta-diketonate first generation precursor. Film depositions were carried out in low-pressure Ar\ub1O2 plasmas at temperatures between 150\ub0C and 300\ub0C.The film microstructure was investigated by glancing incidence X-raydiffraction(GIXRD) and transmission electron microscopy (TEM), while the surface and in-depth chemical composition was studied by X-ray photoelectron spectroscopy (XPS), and secondary ion mass spectrometry (SIMS), respectively. Optical properties were ana- lyzed by UV-vis optical absorption. Nanostructured CeO2-based films, with crystal size less than 6 nm and a controllable CeIV/CeIIIratio,wereobtainedattemperaturesevenlowerthanthatrequiredforprecursorvaporization(170C).Inparticu- lar, TEM analyses showed an island growth mode and different microstructural features as a function of the substrate used