Pb-Ti-O films were prepared by liquid-injection atomic layer deposition (ALD) using H2O as oxygen source after evaluating Ti precursors with different beta-diketonate type ligands, Ti(OC3H7)(2)(C11H19O2)(2) [Ti(Oi-Pr)(2)(DPM)(2)] and Ti(OC5H11)(2)(C10H17O2)(2) [Ti(Ot-Am)(2)(IBPM)(2)], dissolved in ethylcyclohexane. For both Ti precursors, the apparent thermal activation energy of the deposition rate of TiOx films increased at a deposition temperature of about 380 degrees C, and the deposition rate of TiOx films grown at 300 degrees C saturated against the volume of injected Ti precursors. Ti(Oi-Pr)(2)(DPM)(2) was selected for the subsequent Pb-Ti-O film deposition because of its high precursor efficiency and the low temperature dependence of the deposition rate. Pb-Ti-O films were prepared using Ti(Oi-Pr)(2)(DPM)(2) and Pb(C12H21O2)(2) [Pb(TMOD)(2)] at deposition temperatures of 240 and 300 degrees C. The deposition rates of Pb and Ti in the Pb-Ti-O process were higher than those in binary PbO and TiOx processes under the same deposition conditions. The deposition rate of Pb in the Pb-Ti-O process showed a linear increase in response to the injected Pb precursor volume, which was different from the saturated deposition rate of the PbO process. The interface chemistry between the precursors and predeposited cation layers has critical impact on the self-regulated growth mechanism in the multicomponent oxide ALD. (c) 2006 The Electrochemical Society
