Identical sets of thermal oxidation and nitridation experiments were performed because selectively perturbing equilibrium point-defect concentrations by using these surface reactions was a means for identifying the relative importance of various atomic-scale diffusion mechanisms. Bounds were obtained on the fractional contributions of self-interstitials, vacancies and concerted exchange mechanisms to diffusion at temperatures of 1100 and 1000C (tables 6 and 7). The bounds were found by simultaneously solving a system of equations while making only very conservative assumptions. It was found that B and P diffused via a self-interstitial mechanism, whereas Sb diffusion was almost exclusively vacancy-mediated. The As and self-diffusion results, on the other hand, yielded evidence of a dual vacancy-interstitial mechanism plus a possible concerted exchange component.

Fractional contributions of microscopic diffusion mechanisms for common dopants and self-diffusion in silicon A.Ural, P.B.Griffin, J.D.Plummer: Journal of Applied Physics, 1999, 85[9], 6440-6. See also: Applied Physics Letters, 1998, 73[12], 1706-8

Table 6

Diffusivity of Various Diffusants in Si

Table 7

Diffusivity Enhancement or Retardation for Various Dopants in Si