Crystallization of TiO2 thin films grown by atomic layer deposition from TiCl4 and O-3 on RuO2 layers was investigated with the aim to develop alternative methods for preparation of high-permittivity dielectrics with low leakage current density for capacitor structures of memory devices. The lowest substrate temperature allowing reproducible growth of TiO2 with a rate exceeding 0.01 nm per cycle was determined to be around 225 degrees C. The highest deposition temperature used was limited to 450 degrees C because of RuO2 decomposition at higher temperatures. The TiO2 films deposited on RuO2 electrodes at substrate temperatures of 225-450 degrees C contained rutile phase. Reference films deposited on Si substrates were amorphous when deposited at 225 degrees C and contained anatase when deposited at 250 degrees C and higher temperatures. At temperatures 250-450 degrees C, the growth rate values of 10-25 nm thick films ranged from 0.04 to 0.07 nm per cycle being somewhat higher on RuO2 than on Si substrates. The dependence of the mean growth rate on the substrate material was mainly due to differences in nucleation and became weaker with increasing film thickness. Relative permittivity measured for TiO2 in the Pt/TiO2/RuO2 structures at a frequency of 10 kHz ranged from 106 to 126. The TiO2 films with the lowest leakage current densities were grown at 300-350 degrees C. Leakage current densities as low as (5-7) x 10(-8) A/cm(2) at an applied voltage of 0.8 V were recorded for capacitor structures with capacitance-equivalent dielectric thicknesses of 0.41-0.45 nm. (c) 2013 Elsevier B.V. All rights reserved.