MOCVD growth and characterization of ZrO2 thin films obtained from unusual organo-zirconium precursors

ZrO2 thin films were deposited on polycrystalline alumina, glass, [100] silicon, and stainless steel substrates by metal-organic chemical vapor deposition (MOCVD), Depositions were carried out in a hot wall reactor at reduced pressure (0.6 torr) in the temperature range 400-550 degrees C, using zirconium cyclopentadienyl derivatives as precursors, both in a flux of oxygen and of an oxygen/water vapor mixture. High quality zirconia films with high growth rates were obtained by employing (C5H5)(2)Zr(CH3)(2) Scanning electron microscopy (SEM) images display. in both cases, a tapered polycrystalline columnar structure of the deposits. Films grown under O-2 flux show a cracked surface with a variable carbon contamination depending on the experimental conditions, while those prepared in a O-2/H2O mixture are smooth and well adherent to the substrate with 5 % carbon presence according to X-ray photoelectron spectroscopy (XPS) analysis. X-ray diffraction shows that samples grown in O-2 flux consist of the tetragonal phase with a small amount of the monoclinic polymorph, whose percentage increases with the growth temperature. The presence of water vapor led to larger crystalline domains predominantly composed of monoclinic phase.