Chemical vapor deposition of hafnium dioxide thin films from cyclopentadienyl hafnium compounds

Thin films of HfO2 were grown by metal-organic chemical vapour deposition on fused quartz substrates in the temperature range of 400-500 degrees C using some bis(cyclopentadienyl)bis(alkoxide)hafnium (IV) precursors, namely Cp2Hf(O'Pr)(2), [Cp2Hf{OCH(CH3)CH2CH3}(2)], [Cp2Hf{OC (CH3)CH2OCH3}(2)] and [Cp2H{OC(CH2CH3)(2)CH2OCH3}(2)]. These complexes, analyzed by nuclear magnetic resonance and thermogravimetric measurements, resulted pure and very stable towards air and moisture. The obtained films were investigated by X-ray diffraction, X-ray photoelectron spectroscopy and atomic force microscopy. The deposits contained hafnium and oxygen in the right stoichiometric ratio with a low carbon contamination and they consisted of monoclinic HfO2 phase (baddeleyite) with a granular surface morphology