Atomic layer deposition of boron oxide thin films was demonstrated at room temperature using BBr3 and H2O as precursors. Crystallinity of the films was characterised by X-ray diffraction while time-of-flight elastic recoil detection analysis (TOF-ERDA) and X-ray fluorescence were used to analyse stoichiometry and possible impurities. As-deposited films were amorphous and reacted readily with the atmosphere if not protected by an alumina overlayer. Boron oxide deposition rate of 0.76 angstrom per cycle was obtained at 20 degrees C. If the deposition temperature was increased to 50 degrees C and above, almost no film growth could be obtained. According to the TOF-ERDA, hydrogen and carbon contents in the films were very low being less than 0.2 and 0.1 at.%, respectively. (c) 2006 Elsevier B.V All rights reserved.