Published online by Cambridge University Press: 21 March 2011
Understanding the diffusion 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 calcultions in order to gain insight into the fundamental process involved in arsenic activation/deactivation. Utilizing continuum modeling, we find it is possible to account for both the very rapid initial deactivation of arsenic as well as the strongly superline independence of interstitial supersaturation on doping level which accompanies deactivation. The critical process is the rearrangement of A s-atoms via in testitial mediated diffusion leading to ejection of silicon atoms from arsenic complexes and formation of arsenic-vacancy clusters.