The dependence of heavy-ion-induced adhesion on energy loss and time

Publisher Website
Google Scholar
Abstract
The ability of heavy-ion beams to enhance the adhesion of thin metallic films to substrates has been studied as a function of projectile species. Measurements of the adhesion enhancement of a thin gold film to substrates of tantalum and silicon (with native oxides) have been made for beams of 12C, 16O, 28Si, 35Cl, and 58Ni at 2.85 MeV/nucleon. The threshold dose required to pass the Scotch tape peel test was found for the Au-Ta system to be D th (cm−2) = 1017 (dE / dx)−3±0.2 where dE/dx is the electronic stopping power (MeV mg−1 cm−2) of the ion in Au. For the Au-Si system, Dth = 6×1018 (dE/dx)−4.1±0.3. The steep dependence of D th on dE/dx found here is in contrast with an earlier measurement for the Au-Ta system by Tombrello et al. The adhesion enhancement was observed to decrease with time after the bombardment in a manner suggesting that diffusion of atoms through the gold film is important. The possible importance of small concentrations of extraneous atoms at the interface is discussed.