EVOLUTION OF THE MICROSTRUCTURE OF OXIDE THIN-FILMS

The film growth of CeO2 by metal-organic chemical vapor deposition (MO CVD) was studied. Samples of different thicknesses (d = 10-500 nm) on SrTiO3 as well as on yttria stabilized zirconia were prepared and anal ysed by X-ray diffraction (theta/2 theta-scan, omega-scan), scanning e lectron microscopy (SEM), and Rutherford backscattering spectroscopy ( RES). The films grew with a preferential orientation and a CeO2[001]// substrate[001] was found. The rocking: curves in the omega-scans exhib ited a two-component shape in very thin films. A crossover depending o n the substrate material was observed at higher film thicknesses leadi ng to a one-component curve. The complex behavior in the film evolutio n of the CeO2 system will be discussed, and a model of the film growth mechanism will be proposed.