Papers Published

1. Chen, C.H. and Gosele, U.M. and Tan, T.Y., Dopant diffusion and segregation in semiconductor heterostructures. Pt. 2. B in Ge_xSi_1-x/Si structures, Appl. Phys. A, Mater. Sci. Process. (Germany), vol. 68 no. 1 (1999), pp. 19 - 24 [s003390050848] .
   (last updated on 2007/04/10)

   Abstract:
   For pt.1 see ibid., vol.68, p.9-18, 1999. This is the second of a series of papers treating the shallow dopant diffusion and segregation problems in semiconductor heterostructures. Employing a segregation mechanism model, which incorporates the chemical effect, the Fermi-level effect, and the effect of the junction carrier concentrations, satisfactory fits of available boron distribution profiles in Ge_xSi_1-x/Si heterostructures have been obtained. Here the chemical effects seem to be of less importance. The Fermi-level effect determines the ionized boron solubilities in Ge_xSi_1-x and in Si, as well as the thermal equilibrium concentration of the singly-positively-charged crystal self-interstitials I⁺ which governs the boron diffusion process. The junction carrier concentration affects the concentration of I⁺ and solubility of B in the region and hence controls B diffusion across the heterojunction

   Keywords:
   annealing;boron;carrier density;diffusion;doping profiles;elemental semiconductors;Fermi level;Ge-Si alloys;impurity states;segregation;semiconductor heterojunctions;silicon;solubility;