The thermal decomposition mechanism of a novel titanium source, methylpentanediolbis(methoxyethoxytetramethylheptanatedionato) titanium, called Ti(MPD)(METHD)(2), for metallorganic chemical vapor deposition (MOCVD) of titanium-containing oxide films such as high-dielectric (Ba, Sr)TiO3 and ferroelectric Pb(Zr, Ti)O-3 thin films was investigated by in situ infrared absorption spectroscopy. Ti(MPD)(METHD)(2) has additional methoxyethoxy lariat structures compared, with methylpentanediolbis(dipivaloylmethanato)titanium. The temperature dependence of the infrared absorption indicates that the spatial shield of the titanium atom by the methoxyethoxy lariat structures contributes to the higher thermal stability of Ti(MPD)(METHD)(2). An isotopic labeling experiment using O-18(2) was also performed in MOCVD of a titanium oxide film. The deposited film was analyzed by time-of-flight secondary-ion mass spectrometry to determine the extent of O-18 incorporation. The majority of the oxygen in the titanium oxide films was found to originate from Ti(MPD)(METHD)(2). (C) 2004 The Electrochemical Society.