A novel process for atomic layer deposition of thulium oxide (Tm2O3) has been developed, employing TmCp3 as metal precursor and H2O as oxidizing agent. The use of a highly reactive oorganometallic precursor eliminates the need for a strong oxidizing agent (such as O-3) and provides a high deposition rate of similar to 1.5 angstrom/cycle. A thorough characterization of the process has been performed, identifying true ALD-type film growth in the temperature range 200-300 degrees C. The ALD process has been further investigated by extensive physical and electrical characterization of the deposited films in terms of-composition, crystalline phase, surface roughness and extraction of the dielectric constant. The films were found to be oxygen-rich Tm2O3, with low carbon impurity content at low deposition temperature and after annealing at 600 degrees C. The developed process produced polycrystalline films, with a surface roughness <1 nm RMS. Integration in MOS capacitors demonstrated well-behaved CV curves after annealing at 600 degrees C, with a relative dielectric constant of similar to 16. (C) 2013 The Electrochemical Society. All rights reserved.