Room-temperature atomic layer deposition (ALD) of TiO2 was developed using tetrakis(dimethylamino)titanium (TDMAT) and a remote-plasma-excited water vapor. A growth rate of 0.157 nm/cycle at room temperature was achieved, and the TDMAT adsorption and its oxidation on TiO2 were investigated by multiple-internal-reflection infrared absorption spectroscopy. Saturated adsorption of the TDMAT occurs at exposures of 1 x 10(6) Langmuir (1 Langmuir = 1 x 10(-6) Torr s) at room temperature, and the remote-plasma-excited water vapor is effective in oxidizing the TDMAT-saturated TiO2 surface. The IR study suggests that the Ti-OH plays a role of adsorption site for TDMAT. The reaction mechanism of room-temperature TiO2 ALD is discussed. (C) 2014 Elsevier B.V. All rights reserved.