Cluster ripening and transient enhanced diffusion in silicon

Transient enhanced diffusion of boron marker layers following silicon ion implantation shows a complex behavior as a function of annealing temperature and time. In the initial phase of ripening, small clusters with low binding energy give rise to an extremely large interstitial supersaturation (approximately 10⁶-10⁷ at 600 °C). As the clusters ripen into {113} defects the supersaturation drops to a level which remains almost constant with time until the {113} defects have dissolved. By inverse modeling of the Ostwald ripening process, values are extracted for several basic physical parameters: the energy barrier for boron-interstitial association, the dissociation energy E_diss of the migrating boron-interstitial species, and the interstitial self-diffusion product. The data are consistent with recent ab initio predictions that the migrating boron species is a boron-interstitial pair. Analysis of the detailed time evolution of TED allows us to extract E_diss for silicon clusters and {113} defects as a function of defect size, n. We find strong oscillations on E_diss in the size range 2<n<10. For larger clusters E_diss rapidly converges to a near-constant value of about 3.7 eV, characteristic of {113} defects. The results have been initially implemented in the atomistic Monte Carlo simulator DADOS.