Physically based modeling of dislocation loops in ion implantation processing in silicon

Under certain conditions, particularly for high-dose implants, {3 1 1} rod-like defects can evolve into dislocation loops (DLs). In this work, we have developed a model for the transformation of {3 1 1}-defects into DLs, with a transformation rate that is controlled by a size-dependent energy barrier. The model has been included and calibrated in an atomistic kinetic Monte Carlo simulator. This simulator includes a description of the size distribution of {3 1 1}-defects (required for a size-based model) and of the amorphization and recrystallization (needed to provide reliable information on the number of interstitials in the end-of-range region). Extended defects are implemented according to realistic geometries, giving a direct assessment of the correct capture volume for diffusing defects. The model correctly predicts the formation of DLs during the annealing that follows ion implants, both for amorphizing and non-amorphizing conditions, and provides a realistic description of damage morphology. The possible role of stress on DL formation is also discussed.