Macroscopicdescriptionofthediffusionofinterstitialimpurityatomsconsideringtheinfluenceofelasticstressonthedriftofinterstitialspeci-北弘传媒著作.pdf

Macroscopic description of the diffusion of interstitial impurity atoms considering the influence of elastic stress on the drift of interstitial species O. I. Velichko Department of Physics, Belarusian State University of Informatics and Radioelectronics, 6, P. Brovka Street, Minsk, 220013 Belarus, E-mail: oleg velichko@ Abstract The diffusion equation for nonequilibrium interstitial impurity atoms taking into account their charge states and drift of all mo- bile interstitial species in the built-in electric field and in the field of elastic stress was obtained. The obtained generalized equation is equivalent to the set of diffusion equations written for the interstitial impurity atoms in each individual charge state. Due to a number of the characteristic features the generalized equation is more convenient for numerical solution than the original system of separate diffusion equations. On this basis, the macroscopic description of stress-mediated im- purity diffusion due to a kick-out mechanism was obtained. It is sup- posed that the interstitial impurity atom makes a number of jumps before conversion to the substitutional position. At the same time, a local equilibrium prevails between substitutionally dissolved impu- rity atoms, nonequilibrium self-interstitials, and interstitial impurity atoms. Also, the derived equation for impurity diffusion due to the kick-out mechanism takes into account all charge states of interstitial impurity atoms as well as drift of interstitial species in the electric field and in the field of elastic stress. Moreover, this equation