Atomistic simulation of defect formation and evolution in Si within the first 100 - 1000 ps after ion impact

Ion bombardment causes atomic collisions and the displacement of target atoms. The subsequent athermal and rapid thermal relaxation processes lead to a (meta)stable defect structure which can still be changed by thermal activation. The initial stage of defect formation occurs on very small time and length scales and is therefore hardly accessible by available experimental methods. Therefore, atomistic computer simulations are employed to investigate these processes and to determine the (meta)stable defect structure formed. The knowledge of details of this damage state, e.g. of type and amount of defects, can contribute to a better understanding of ion implantation and ion-assisted layer deposition.
In this talk, a combined atomistic simulation method is used to study a relatively simple case, the defect formation by a single ion impact in bulk silicon. The procedure allows the effective calculation of the total number and the depth distribution of different defect species (isolated vacancies and self-intersitials as well as more complex defects) formed on average per incident ion. Furthermore, it enables investigations on the temporal evolution of the defect structure up to several 100 ps after ion impact, and on the influence of the target temperature on this process.