MICROSCOPIC THEORY OF SELF-DIFFUSION AND IMPURITY DIFFUSION IN SILICON.

Abstract

The authors review briefly our recent calculations of formation and migration energies of vacancies and self-interstitials which led to the following: The self-interstitial can migrate athermally, in agreement with data, along several paths. The observed high-temperature self-diffusion activation energy can be accounted for in terms of both the vacancy and interstitial mechanisms, without the need to invoke a change in the nature of intrinsic defects as a function of temperature. In addition, the authors report new results on the energetics of dopant impurities (Al and P). It is found that the diffusion mechanism of these impurities involves both vacancies and self-interstitials and is considerably more complex than the corresponding self-diffusion mechanisms.