Structural and optical properties of thin lead oxide films produced by reactive direct current magnetron sputtering

The structural and optical properties of thin lead oxide films were studied . Thin films were prepared by reactive dc magnetron sputtering of lead (Pb) targets in an Ar/O-2 mixture. The structure has been determined by x-ray d iffraction measurements, which show that crystalline lead oxide films of di fferent composition (PbO, PbO1.44, Pb2O3, and PbO2) have been formed upon i ncreasing oxygen flow (partial pressure). This result is confirmed by Raman spectroscopy. The effect of postdeposition annealing on the structural pro perties of PbO films reveals that the film structure is governed by both en ergetics and kinetics. X-ray reflectivity measurements were used to determi ne the thickness, density, and roughness of the films. The calculated film density values are almost equal to the bulk density of the material, showin g that compact, nearly void free films are formed. The optical properties o f the films have been studied from the reflectance and transmittance spectr a recorded by optical spectroscopy measurements from 10 000 (1.24 eV) to 50 000 (6.21 eV) cm(-1). From these data we have determined optical propertie s such as the dielectric function, the optical band gap E-g and the refract ive index n as well as the film thickness. (C) 2001 American Vacuum Society .