A review was presented of the possibilities opened up by the development of the Monte Carlo binary collision approximation simulation of Rutherford back-scattering spectrometry channeling spectra for the study of radiation damage in monocrystalline materials. The ion implantation of Si was chosen as a case study. Atomic-scale modeling of defect structures was used to determine the location of interstitial atoms in the host lattice. Among possible candidate defects, were the elementary hexagonal, tetrahedral, <110>-split interstitials, the Bond-defect and one type of tetra-interstitial cluster. For each defect model, a large Si super-cell was populated with a proper defect depth distribution and was then structurally relaxed by the application of the classical EDIP potential. This model system was then used as the input to the Monte Carlo binary collision approximation simulation code and the spectra corresponding to 9 different axial and planar alignments were calculated. For defect concentrations of a few at%, the scattering yields depended strongly upon the orientation. A distinct signature which was characteristic of the limited number of allowed interstitial positions in Si was found. A comparison of simulations and experiments in the case of 180keV self-ion implantation permitted the identification of the dominant interstitial defect; whose structural properties were represented by a split-<110> interstitial. Upon increasing the concentration of defects, and their mutual interaction, the technique lost sensitivity and the contribution of lattice relaxation became important. Under these conditions, although the Rutherford back-scattering spectrometry channeling response became similar to that obtained from a random distribution of displaced atoms, the major structural features of a heavily damaged sample could still be observed.

Channeling Characterization of Defects in Silicon - an Atomistic Approach. M.Bianconi, E.Albertazzi, S.Balboni, L.Colombo, G.Lulli, A.Satta: Nuclear Instruments and Methods in Physics Research Section B, 2005, 230[1-4], 185-92