Iridium (Ir) thin films, deposited on Si (1 0 0) substrate by pulsed laser deposition (PLD) technique using Ir target in a vacuum atmosphere, were annealed in air ambient and the thermal stability was investigated. The crystal structure and surface morphology of Ir thin films before and after being annealed were studied by X-ray diffraction, Raman scattering, scanning electron microscope, and atomic force microscopy. The results showed that single-phase Ir thin films with (1 1 1) preferred orientation could be deposited on Si (1 0 0) substrate at 300 degrees C and it remained stable below 600 degrees C, which showed a promising bottom electrode of integrated ferroelectric capacitors. Ir thin films got oxidized to IrO2 at temperatures from 650 to 800 degrees C. (C) 2007 Elsevier B.V. All rights reserved.