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

Abstract

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 10 14 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.