Papers Published

1. Yu, S. and Tan, T.Y. and Gosele, U., Diffusion mechanism of zinc and beryllium in gallium arsenide, J. Appl. Phys. (USA), vol. 69 no. 6 (1991), pp. 3547 - 65 [1.348497] .
   (last updated on 2007/04/10)

   Abstract:
   The outstanding features associated with Zn and Be diffusion in GaAs substrates and GaAs/AlGaAs superlattices are explained either quantitatively or semiquantitatively using the kick-out mechanism, in which it is assumed that the doubly positively charged Ga self-interstitial governs Ga self-diffusion. These features include: (i) the dependence of the Zn solubility upon the pressures of the As and Zn vapor phases, (ii) the square power-law dependence of the Zn diffusivity on its own background concentrations under Zn isoconcentration diffusion conditions, (iii) the different shapes of the Zn in-diffusion profiles, (iv) the much lower diffusivities of Zn and Be under out-diffusion conditions than under in-diffusion conditions, and (v) the tremendous enhancement effect of Zn in-diffusion on GaAs/AlGaAs superlattice disordering and the undetectable effect of Be under out-diffusion conditions. Some useful quantitative information has been obtained. Strictly on a qualitative basis, the authors have found that the Longini mechanism is also able to explain the features (i)-(iv) fairly well. The predicted effects of the Longini mechanism on Ga self-diffusion are, however, contrary to experimental results associated with superlattice disordering

   Keywords:
   aluminium compounds;beryllium;diffusion in solids;gallium arsenide;III-V semiconductors;interstitials;semiconductor superlattices;substrates;zinc;