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 GexSi1-x/Si heterostructures have been obtained. Herl the chemical effects seem to be of less importance. The Fermi-level effect determines the ionized boron solubilities in GexSi1-x and in Si, as well as the thermal equilibrium concentration of the singly-positively-charged crystal self-interstitials I+ which governs the baron 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. [References: 15]

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