Substrate biasing has been implemented in a remote plasma atomic layer deposition (ALD) reactor, enabling control of the ion energy up to 260 eV. For TiO2 films deposited from Ti(Cp-Me)(NMe2)(3) and O-2 plasma it is demonstrated that the crystalline phase can be tailored by tuning the ion energy. Rutile TiO2 was obtained at 200 and 300 degrees C, typically yielding amorphous and anatase films without biasing. Aspects such as film mass density, [O]/[Ti] ratio and growth per cycle under biased conditions are addressed. The results demonstrate that substrate biasing is a viable method for ALD to tailor ultra-thin film properties. (C) 2011 The Electrochemical Society. [DOI: 10.1149/2.024202esl] All rights reserved.