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-<110> 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 10(14) cm(-1). This process produces a 0.7 mum damaged region, with a few atomic percent maximum damage concentration. The RBS-channeling measurements were performed with a 2 MeV He beam aligned along <100>, <110>, <120>, <130>, <111>, <112>, <113> axes and {100}, {110} 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 <110>-split relaxed interstitial.