The out-diffusion of an impurity by the kick-out mechanism during gettering was analyzed by numerical solution of the set of diffusion-kinetic equations. For the example of Au impurity in Si, the effect of the degree of gettering and the dislocation density upon the concentration profiles of the impurity and self-interstitials was investigated. It was shown that the usually used approximation, based upon the solution to diffusion equations for a substitutional impurity with effective diffusivities could lead to an underestimation of the gettering time. In the absence of dislocations, this underestimation was caused by modifying the expression for effective diffusivity in the case of gettering and violating the local-equilibrium condition at the gettering front. For a high dislocation density, the process of lowering the impurity-concentration level was caused by the kinetics of generation of self-interstitials on dislocations instead of the impurity diffusion.

Out-Diffusion of Impurity via the Kick-Out Mechanism during Gettering. O.V.Aleksandrov, A.A.Krivoruchko: Semiconductors, 2007, 41[9], 1048-55