Influence of the Low-Energy Inert-Gas Ion Bombardment on the Structure and Properties of Metallic Thin Films

Abstract

The goal of the review is to analyse the main published results of the most systematic studies of changes in the structural–phase state, the physical and chemical properties of the metallic single- and multilayer thin films’ systems after bombardment by the low-energy (< 10 eV) inert-gas ions. Nanoscale film systems are obtained using two widespread physical methods: magnetron deposition and thermal resistive evaporation. The single-layer systems are based on such pure metals as Co, Cu, Ni, Pt, Nb, Ti, Fe, and W. The films deposited on the Si(100) substrate have thicknesses in the range of 25–700 nm. Multilayered thin films are fabricated based on the following combinations: Cu/Ni, Ni/Cu/Cr, Cr/Cu/Ni, and Ni/Cu/V with 25–30 nm thickness of each layer. The low-energy inert-gas ions’ (Xe+, Ar+, Ne+, He+) bombardment with varying beam energy in the range of 200–10000 eV and fluence in the range of 1015–1019 ions/cm2 are used. The ion bombardment-induced morphology, microstructure and chemical evolution of the polycrystalline thin films are studied using x-ray diffraction (XRD), secondary ion mass spectrometry (SIMS), Auger-electron spectroscopy (AES), electrography, transmission electron microscopy (TEM), scanning electron microscopy (SEM), atomic force microscopy (AFM), and tribological tests. Different physical mechanisms contributing to this evolution and their relation to theoretical models and experimental studies of the ion-induced thin films are discussed.

Keywords

• thin films
• ion bombardment
• surfaces
• phase transformations
• wear resistance