Platinum films to be used as a substrate and as a bottom electrode for the growth of ferroelectric materials should be able to withstand the thermal budget specific to the deposition method of the ferroelectric layer without being degraded. Annealing of platinized Si wafers in nitrogen and nitrogen:oxygen ambient conditions was performed in a similar fashion as prior to metalorganic chemical vapor deposition of ferroelectric thin films. The consequent induced modifications of the initial morphology, composition, and structure of the Pt wafers were studied, respectively, by atomic force microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy and X-ray diffraction. The observations were related to the optical properties of the annealed Pt wafer by creating a model fitting ellipsometry data. Using this technique, the roughening at room temperature of a platinized wafer was monitored for 15 months starting shortly after the wafer was being processed. These results indicate that the Pt wafers are also aging at room temperature. (C) 2003 Elsevier Science B.V. All rights reserved.