A computational study of ion-implanted beryllium diffusion in gallium arsenide

• Published in: Computational materials science 2008-10, Vol.43 (4), p.902-908
• Main Authors: Koumetz, S.D., Pesant, J.-C., Dubois, C.
• Format: Article
• Language: English
• Subjects: 61.72.Cc; 61.72.U; 61.72.uj; 66.30.J; 68.49.Sf; 82.80.Ms; Condensed matter: structure, mechanical and thermal properties; Defects and impurities in crystals; microstructure; Diffusion; Diffusion in solids; Diffusion of impurities; Doping and impurity implantation in iii-v and ii-vi semiconductors; Exact sciences and technology; GaAs; Ion implantation; Physics; RTA; SIMS; Structure of solids and liquids; crystallography; Transport properties of condensed matter (nonelectronic)
• ISSN: 0927-0256; 1879-0801
• DOI: 10.1016/j.commatsci.2008.02.003

The diffusion of implanted beryllium in gallium arsenide at 100keV for doses of 1×1013 and 1×1014cm−2 during post-implant RTA were studied and simulated at temperatures of 700–900°C for 1–4min. The observed Be diffusion profiles, obtained by the SIMS technique, can be satisfactorily explained in terms of a “kick-out” model of the substitutional-interstitial diffusion mechanism, involving singly ionized Be and doubly ionized Ga interstitial species. The generation of the excess Ga interstitials, according to the “plus-one” approach, and its annihilation in the local Ga interstitial sink region were taken into account. The corresponding coupled partial differential equations of the relevant diffusion model were solved numerically with proper initial and boundary conditions using the computational algorithms based on finite-difference approximations.