Titania and hafnia thin films were deposited by atomic layer deposition using metal alkoxides and carboxylic acids as oxygen source. The effect of annealing under nitrogen on the densification of the films and on the resulting electrical properties is presented. The as-deposited and annealed films demonstrate good dielectric permittivity and low leakage current densities due to their purity and amorphous character. (C) 2009 American Vacuum Society. [DOI: 10.1116/1.3058743]