Effects of post-growth annealing on physical properties of SrRuO3 thin film grown by MOCVD

We report on the annealing effects on strontium ruthenate thin films deposited on SrTiO3 using liquid-delivery metalorganic chemical vapor deposition (MOCVD). The results of high resolution X-ray diffraction (HR-XRD), Raman spectroscopy, atomic force microscopy (AFM), and electrical resistivity, before and after a post-growth annealing process were analyzed and compared. XRD and Raman spectroscopy for the as-deposited film revealed that the film had c-axis orientation and contained RuO2 as secondary phase. Single phase SrRuO3 could be obtained by annealing the film at 700 degrees C. Annealing at higher temperatures up to 850 degrees C leads to ruthenium deficiency, which is revealed by an increase in the out-of-plane lattice parameter, while at even higher annealing temperatures a decrease in the out-of-plane lattice parameter was detected might be due to diffusion of Ti from the substrate. The electrical resistivity increased with increasing annealing temperatureup to 950 degrees C and showed typical metallic temperature dependence, while for the film annealed at 1000 degrees C a semiconductor-like behavior was observed. (C) 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim