Electronic-loss induced ion beam mixing in various materials studied using SIMS technique

Ion beam mixing of multilayer thin films using MeV ion irradiation is described in this paper. Iodine ion beam irradiation at 90 and 100 MeV on Fe/Si, Ti/Si, Fe/Ti, Zr/Si and Zr/Ti multilayer thin films are carried out such that electronic losses predominate and the ions do not get implanted in the films. Ion irradiation fluences range from 1×1013 ions/cm2 to 1×1014 ions/cm2. Depth profiles of the films at various interfaces are measured using SIMS technique. The interface profile in each case is fitted with a complementary error function to determine the diffusion lengths of species A in species B or vice versa in multilayer A/B films. Mixing is observed at Fe/Si, Ti/Si and Zr/Si interfaces and no mixing at Fe/Ti and Ti/Zr. The mixing rate in Si/Ti films is higher at an ion dose of 5×1013 ions/cm2 than at 2.5×1013 ions/cm2. In an Fe/Si system, complete mixing is observed. It is concluded that the amorphous nature of Si is responsible for inducing mixing in the present experiments.