Laser-induced metal organic decomposition for Ce0.9Zr0.1O2−y epitaxial thin film growth

Abstract

Cerium–zirconium propionates precursor layers were decomposed by pulsed laser radiation for the development of epitaxial Ce0.9Zr0.1O2−y (CZO) thin-films on yttria-stabilized zirconia (YSZ) (001) single crystal substrates. The laser treatments were performed by means of a Nd:YAG laser system (λ=266nm, τ=3ns, ν=10Hz). The influence of processing parameters such as the laser fluence, number of pulses and substrate temperature on the morphology, surface roughness and composition of the irradiated material was studied and correlated with the optical properties and thermochemical characteristics of the propionate precursors. We conclude that the metal organic decomposition proceeds both from direct optical absorption of the precursor film and from the heating effect associated to the optical absorption of the YSZ substrate. FTIR spectra allow us to define the laser irradiation conditions where a full elimination of the organic precursors is achieved. After the metal organic precursor decomposition, we investigated the thin films crystallization process through furnace annealing. Our analyses demonstrate that through an optimized laser treatment and a furnace heating process it is possible to create epitaxial 20nm-thick CZO films, with similar nanostructure and surface flatness than in conventional thermal treatments but with an important saving of processing time and an enhanced versatility to define micrometric patterns.