Analysis of ion implanted silicon by RBS-channeling: influence of the damage model

In this work two different models of damage have been applied to the binary collision approximation Monte Carlo simulation of the RBS-channeling spectra of ion implanted silicon. We compare a widely used description of interstitial defects consisting of randomly displaced atoms in an unperturbed lattice with a model based on split-<1 1 0> interstitials combined with the induced lattice relaxation, as calculated by the application of the EDIP potential. The sample was prepared by 180 keV Si implantation with dose 1014 cm-2. This process produces a 0.7 μm damaged region, with a few atomic percent maximum damage concentration. The RBS-channeling measurements were performed with a 2 MeV He beam aligned along <1 0 0>, <1 1 0>, <1 2 0>, <1 3 0>, <1 1 1>, <1 1 2>, <1 1 3> axes and {1 0 0}, {1 1 0} planes. By making use of the two beam model, we show that the experimental data set can be normalised to display a characteristic signature of the defects present in the sample and that this signature is compatible with the <1 1 0>-split relaxed interstitial