Some particular features of the condensation process, structure and properties of thin metal films caused by self-ion bombardment

This communication contains a brief review and analysis of our previous and recent results on the influence of self-ion bombardment during deposition (ion energy Ei = 0–5 keV, specific power Wi = 0–6 W/cm2) on the structure and properties of Nb, TixSiy and Al films. The results have been received under ordinary vacuum conditions ∼ 10−6 Torr and typical condensation rates ∼ 1–10 nm/s. Some particular features of self-ion bombardment effects are noted, which are not typical for such vacuum conditions and/or for other ion-assisted deposition methods: preparation of ultra-thin (10–30 nm) Nb films with superconductive transition temperature Tc = 7–8 K and resistance ratio R300 KR10 K = 2–3, formation of perfect textures in Nb and Al films with a disperse angle of 2.5° and 5°, respectively, rapid formation of single-phase TiSi2 films with low resistivity ∼ 13–15 μΩ·cm, high grain boundary migration rate and large grain sizes (up to 11 μm of the average value) in Al films. The energetic parameters of the deposition such as specific energy, effective condensation rate, and specific power of self-ion bombardment are characterized as critical. The ion bombardment influences the structure and properties of the films by essentially different mechanisms in different ranges of the values of these parameters.