PbxPty alloy formation and its influence on Pb (Zr, Ti)O-3 (PZT) film growth during liquid-delivery metallorganic chemical vapor deposition (MOCVD) of ferroelectric PZT thin films on Pt electrodes are investigated. When an excessive amount of Pb precursor and a deficient amount of oxygen are supplied during MOCVD at temperatures near 550 degrees C, Pb diffuses along the grain boundaries into the Pt substrate, causing the formation of an alloy layer. Compared to a thicker Pt electrode (150 nm), a thinner Pt substrate (50 nm) enhances the alloy layer formation due to the higher diffusion of Pb along the more abundant Pt grain boundaries. The alloy layer enhances the Pb incorporation into the PZT film and improves the crystallization of the PZT layer on top due to better structural compatibility between PZT and the alloy. When the deposition temperature is 570 degrees C the alloy formation is initiated in the early stage of the film deposition but undergoes thermal decomposition in the later stage ( > similar to 15 min ). Therefore, a constant Pb concentration is obtained after the initial decrease for a deposition period < 15 min. (c) 2006 The Electrochemical Society.