Liquid-Injection Atomic Layer Deposition of TiO[sub x] and Pb–Ti–O Films

Abstract

PbTiO films were prepared by liquid-injection atomic layer deposition ALD using H2O as oxygen source after evaluating Ti precursors with different -diketonate type ligands, TiOC3H72C11H19O22 TiOiPr2DPM2 and TiOC5H112C10H17O22 TiOtAm2IBPM2, 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 380C, and the deposition rate of TiOx films grown at 300C saturated against the volume of injected Ti precursors. TiOiPr2DPM2 was selected for the subsequent PbTiO film deposition because of its high precursor efficiency and the low temperature dependence of the deposition rate. PbTiO films were prepared using TiOiPr2DPM2 and PbC12H21O22 PbTMOD2 at deposition temperatures of 240 and 300C. The deposi- tion rates of Pb and Ti in the PbTiO process were higher than those in binary PbO and TiOx processes under the same deposition conditions. The deposition rate of Pb in the PbTiO 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. 2006 The Electrochemical Society. DOI: 10.1149/1.2219709