Study of ion scattering and dechanneling from surface defect structure by computer simulation

The dechanneling effects of the low-energy Ne+ and Ar+ ion scattering from atomic steps on Cu(1 0 0) and GaP(1 0 0) surface at grazing incidence have been investigated by computer simulation. The energy distributions of particles scattered by the isolated atomic steps consisting of several atoms have been calculated. It has been shown that from the correlation of the experimental and calculated energy distributions of the scattered particles, one may determine a spatial extension of the isolated atomic steps and distance between them on the single-crystal surface damaged by ion bombardment. The ions dechanneling from semi-infinite steps on the GaP(1 0 0) surface as well as the trajectories of these particles have been studied. The energy and angular distributions of the dechanneling ions have been calculated. It was shown that the dechanneling ions form the characteristic peaks in the angular and energy distributions of scattered ions.