MD simulation of ion implantation damage in AlGaAs: I. Displacement energies

Classical molecular dynamics computer simulations using a modified Tersoff potential are used to investigate the generation of point defects in AlxGa1−xAs crystals caused by Al, Ga and As recoils of energies in the range of 7-50 eV. The crystals are kept at room temperature and the composition x is varied between 0 and 1. The results show that the displacement energy for Al is remarkably larger than that of Ga or As and that the displacement energy of As depends considerably on the composition x while that of Al and Ga only weakly depend on x. This can be explained on the base of the main processes contributing to the generation of Frenkel pairs which are obtained by the investigation of all point defects generated and by analyzing the trajectories of the recoils.