Modeling of Annealing of High Concentration Arsenic Pro les

Understanding the di usion and activation of arsenic is critical for the formation of low resistance ultra-shallow junctions as required for nanoscale MOS devices. In this work, we use results of ab-initio calculations in order to gain insight into the fundamental processes in volv edin arsenic activation/deactivation. Utilizing continuum modeling, we nd it is possible to accoun t for both the very rapid initial deactivation of arsenic as well as the strongly superlinear d pendence of interstitial supersaturation on doping level which accompanies deactivation. The critical process is the rearrangement of As atoms via in terstitial mediated di usion leading to ejectionof silicon atoms from arsenic complexes and formation of arsenic-vacancy clusters.