The vacancy and interstitial components of the effective P diffusion coefficient, and the controlling process of P diffusion, were estimated on the basis of the vacancy and interstitial mechanisms for pair diffusion. Upon assuming that the interstitial mechanism was predominant, the interstitial concentration and its gradient were both found to affect the interstitial component of P diffusion at high P contents. The effective interstitial component was large for negative gradients of the interstitial concentration, and was small for positive gradients of the interstitial concentration. The P atoms and interstitials were generated by the dissociation of P-I pairs. When the excess interstitials thus generated were removed, a negative gradient of the interstitial concentration was obtained. This was also the result of a decrease in quasi self-interstitial formation energy. Several diffusion models simulated the P diffusion profile well under an inert atmosphere, and this made it difficult to conclude which model was correct. It was suggested that it was possible to decide this on the basis of the P profile during oxidation.

Effective Diffusion Coefficient and Controlling Process of P Diffusion in Si Based on the Pair Diffusion Models of Vacancy and Interstitial Mechanisms. M.Yoshida, M.Morooka, M.Takahashi, H.Tomokage: Japanese Journal of Applied Physics - 1, 2000, 39[5A], 2483-91