It was recalled that C diffusion was usually assumed to be governed by C interstitials via the kick-out mechanism. Also, C in-diffusion experiments were associated with thermal equilibrium concentrations of point defects whereas, in the case of C out-diffusion, a notable undersaturation of Si self-interstitials could develop provided that the C concentration was several orders of magnitude above its solubility. New C out-diffusion experiments demonstrated that this model qualitatively described observed C diffusion profiles. However, it was demonstrated that an accurate description of the experimental profiles was possible only if the Frank-Turnbull mechanism, which involved vacancies, was also taken into account. Detailed investigations of C and B profiles in the same sample could be used to determine the splitting of the known vacancy component, of the Si self-diffusion coefficient, into a vacancy diffusion coefficient and a vacancy thermal equilibrium concentration at 900C.

The Contribution of Vacancies to Carbon Out-Diffusion in Silicon R.F.Scholz, P.Werner. U.Gösele, T.Y.Tan: Applied Physics Letters, 1999, 74[3], 392-4