Preparation of ZrO2 films with nanometer thickness has been examined using an atomic layer deposition technique under atmospheric pressure utilizing the alternate reaction of ZrCl4 and O-2. The ZrO2 films obtained at 773 K were polycrystalline with tetragonal phase, suggesting that the grain size of crystallites is very small. The growth mechanism is governed by the self-limiting adsorption reaction of ZrCl4 onto a glass substrate with a reasonably smooth surface. (C) 2002 The Electrochemical Society.