Influence of the ion impact azimuth on glancing-incidence keV ion impact on the Si(100) surface

Using molecular-dynamics simulation, we study the impact of 3 keV Ar+ and Xe+ ions at glancing incidence onto the Si(100) surface. The (2 × 1) reconstructed surface forms subsurface channels, which are able to trap the incoming ions. We choose two azimuth angles of the impinging ions, parallel and perpendicular to the dimer rows on the target surface. Surface steps allow glancing ions to enter these subsurface channels. The probability of subsurface channeling is pronouncedly larger for ion impact along the dimer rows, since for this azimuth the subsurface channels have a larger cross section. Finally, our simulation results demonstrate that surface-channeling events can be identified by their characteristic damage features.