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 cm2. This process produces a 0.7 micron 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 <1 1 0>-split relaxed interstitial.