TiN thin films deposited by ion beam sputtering: effects of energetic particles bombardment

The low energy broad argon ion beam (1.35-2.0) keV was used for sputtering of a Ti target in an atmosphere of nitrogen gas to form TiN films. During deposition the growing thin film was under argon ion irradiation from the beam periphery. The influence of the ion beam energy (E-b) and average energy delivered by assisting ions to condensing film atoms (E-n) on TiN film properties was investigated. The titanium nitride thin films were deposited at a low working pressure of 1 x 10(-4) mbar and at ambient substrate temperature. XRD analysis revealed the formation of a delta-TiN phase with preferred (220) orientation for the stoichiometric composition of TiN films (RBS). The increase of both the intensity of the (220) peak and TiN film crystallite dimension with increasing the energy of Ti target bombarding Ar+ ions (E-b) was observed. By increasing the average ion energy per deposited metal atom (E-n) the (220) peak intensity and crystallite dimension decrease and a complete loss of (220) orientation at E-n close to 162 eV/at was found. In the range of E-n considered, the TiN films grain size decreases leading to the nanostructured surface as revealed by the STM analysis. The incident angle and energy of the assisted bombarding strongly influence the film-preferred orientation and sub-microstructure. (C) 2003 Elsevier B.V. All rights reserved.