Infra-red absorption experiments and ab initio computer simulations were used to study Sn-C centers in Si. Electron irradiation of C- and Sn-doped Si led to prominent absorption lines at 873.5 and 1025/cm. These were attributed to a C interstitial trapped by a substitutional Sn atom. The calculated modes were in good agreement with those observed. The calculations also suggested that a nearby pair of substitutional C and Sn will be a stable but electrically inert defect. This defect may account for the experimentally observed drop in the concentration of the Cs-Ci defect after room-temperature annealing. Finally, it was suggested Sn-C co-doping of Si for manufacturing of radiation hard Si.

Carbon-Tin Defects in Silicon. E.V.Lavrov, M.Fanciulli, M.Kaukonen, R.Jones, P.R.Briddon: Physical Review B, 2001, 64[12], 125212 (5pp)