The relative contributions of interstitials and vacancies to the diffusion of a dopant were specified by defining an interstitial fraction of diffusivity, f. It was noted that accurate knowledge of f was required for predictive simulations of processes during which the point defect population was perturbed; such as transient enhanced diffusion. Experimental determination of f was usually based upon an underdetermined system of equations, but it was shown here that it was possible to derive expressions that gave meaningful bounds on f without making any other assumptions beyond that of local equilibrium. By using a pair of dopants, in the presence of the same point-defect perturbation, and by using perturbations that were very far from equilibrium, experimentally determined values of fB (greater than 0.98) were found at around 800C. These were the strictest bounds which had been reported thus far. The results were in agreement with the theoretical prediction that a substitutional dopant in Si should be a pure vacancy, or a pure interstitial(cy) diffusant.

The Interstitial Fraction of Diffusivity of Common Dopants in Si. H.J.Gossmann, T.E.Haynes, P.A.Stolk, D.C.Jacobson, G.H.Gilmer, J.M.Poate, H.S.Luftman, T.K.Mogi, M.O.Thompson: Applied Physics Letters, 1997, 71[26], 3862-4