TiO2 thin films were grown on Ru, Pt, Al2O3-passivated Ru, and Si substrates by plasma-enhanced atomic layer deposition at 280 C. The Ru-substrate-enhanced growth (similar to 3 times higher than that on Si at <100 cycles) was attributed to the electron donation and the diffusion of previously contained oxygen from Ru onto the growing surface. When the Al2O3 layer was interposed between the Ru substrate and TiO2 film, even as thin as 0.4 nm, the electron donation was largely suppressed. Above 16-20 nm, the growth rates of rutile TiO2 (on Ru) and anatase TiO2 (on Si) were 0.055 and 0.04 nm/cycle, respectively. (C) 2009 The Electrochemical Society. [DOI: 10.1149/1.3269901] All rights reserved.