Optical properties of Pb(ZrxTi1−x)O3 (x = 0.4, 0.6) thin films on Pt-coated Si substrates studied by spectroscopic ellipsometry

Lead zirconate titanate Pb(ZrxTi1−x)O3 thin films with Zr/Ti ratio 40/60 (PZT40/60) and 60/40 (PZT60/40) were grown on Pt/Ti/SiO2/Si(1 0 0) substrates by a sol–gel process. Structure, surface morphologies and root mean square (rms) roughness of the thin films were studied by X-ray diffraction (XRD) and atomic force microscopy (AFM). On the surface images of the thin films, many clusters are found, which are composed by grains in size of about 0.5–1 and 0.15–0.2 μm, respectively for the PZT40/60 and PZT60/40 thin films. The rms roughnesses of the PZT40/60 and PZT60/40 thin films are 2.1 and 6.7 nm, respectively. The refractive index n, the extinction coefficient k and thickness of PZT40/60 and PZT60/40 thin films annealed at 600 °C were obtained by spectroscopic ellipsometry as a function of the wavelength in rang from 270 to 1700 nm.