The diffusion of antimony in heavily doped and n- and p-type silicon

The diffusion of Sb in heavily doped n- and p-type Si has been studied to determine the activation energies and charge states of the point defects responsible for Sb diffusion. It is shown that neutral point defects, probably V-x, dominate under intrinsic doping conditions. For samples doped with high-concentration As or P backgrounds, Sb diffusion is dominated by a double-negatively charge point defect that causes an n(2) concentration-dependent Sb diffusivity. Electric-field effects also are important. The measured diffusion coefficients are D-i(x) = 17.5 exp(-4.05 eV/kT), and D-i(-) = 0.01 exp(-3.75 eV/kT). The activation energies are consistent with diffusion via V-x and V- vacancies. Retarded diffusion of Sb in p(+)-doped samples with uniform B profiles fits an ion pairing model where Sb B pairs form to reduce the flux of Sb atoms.