Deposition of CaZrO3 thin films by EB-PVD: Effects of substrate on the composition, the structure, the morphology and the optical properties

Abstract

CaZrO3 thin films have been prepared using the electron beam physical vapor deposition (EB-PVD) technique. To study the effect of the substrate's nature on the physical properties of the films, films of calcium zirconate were grown onto two different substrates; amorphous glass and single-crystalline silicon under the same deposition conditions. It was found that the nature of the substrate affects the structure, morphology, and optical properties of the prepared films. The composition of elements and the thicknesses were analyzed by Rutherford backscattering spectrometry. It was found that films grown onto glass substrates show homogeneous single layers without inter-diffusion, however, an interfacial layer was detected between the substrate and the CaZrO3 film for the films deposited on silicon. The crystalline structure and the purity of the prepared thin films were investigated by X-ray diffraction. The morphology and the surface roughness of the prepared thin films were investigated using scanning electron microscopy and atomic force microscopy. The morphology of the growing films was found to be strongly dependent on the substrate surface, as the films on the silicon substrate exhibit relatively smoother surfaces than those on glass. UV-Visible diffuse reflectance spectroscopy reveals that thin films deposited on silicon show the highest optical bandgap.