The transient enhanced diffusion of low- and high-dose implanted Be in undoped material during post-implantation rapid thermal annealing (700 to 900C, 60 to 240s) was studied and successfully simulated by the kick-out diffusion model, involving singly positively charged Be interstitials and doubly positively charged Ga self-interstitials. Using the so-called +1 approach for Ga interstitial generation after implantation with the local Ga interstitial sink concept as well as the appropriate initial and boundary conditions for involved mobile species, and taking into account Fermi-level and built-in electric field effects, the obtained partial differential equations were solved numerically by means of an explicit finite difference method. The thermal equilibrium concentrations and the diffusivities of Be and Ga interstitials, all as a function of temperature, were deduced from the fits of the experimental profiles obtained by the secondary ion mass spectrometry technique.

Diffusion Mechanism of Implanted Be in GaAs. S.D.Koumetz, J.C.Pesant, C.Dubois: Physica Status Solidi B, 2008, 245[1], 62-9