Authors: S. Dunham, P. Fastenko, Z. Qin and G. Henkelman
Affilation: University of Washington, United States
Pages: 100 - 103
Keywords: arsenic, diffusion, activation, lattice Monte Carlo
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 combine the results of ab-initio calculations with continuum and kinetic lattice Monte Carlo (KLMC) simulations in order to gain insight into the fundamental processes involved in arsenic diffusion and activation/deactivation. By including both interstitial and vacancy-mediated diffusion processes, we find it is possible to account for both the very rapid initial deactivation of arsenic as well as the strongly superlinear dependence of interstitial supersaturation on doping level which accompanies deactivation. The critical process is the rearrangement of As atoms via diffusion leading to ejection of silicon atoms from arsenic clusters which are favorable for vacancy incorporation.