The surfaces of  SrTiO 3 substrates were modified by implantation of 400 keV Ne 2+ ions at 77 K at doses of 5 × 10 14, 10 15 and 5 × 10 15ions/ cm2. Superconducting YBa 2Cu 3O 7 - x thin films were then deposited on these substrates by the electron beam co-evaporation and post-annealing process. The microstructure and properties of these films were characterized by various techniques and compared to a reference film that was grown on an unirradiated SrTiO 3 substrate. The film on the substrate irradiated at the highest dose (5 × 10 16ions/ cm2) showed a deterioration of its properties as reflected by a loss in epitaxy, decrease in transition temperature and increase in transition width. However, films grown on the substrates irradiated at the lower doses showed improvements in the properties as compared to the reference film. The best film was obtained on the substrate irradiated at 10 15 ions/cm 2. This film exhibited a significant improvement in epitaxy and an increase in the transition temperature as compared to the reference film.