Diffusion of Ion‐Implanted B in High Concentration P‐ and As‐Doped Silicon

The diffusion of ion‐implanted B in Si in the presence of a uniform background of high concentration P or As has been studied by correlating numerical profile calculations with profiles determined by secondary‐ion mass spectrometry (SIMS). Retarded B diffusion is observed in both As‐ and P‐doped Si, consistent with the effect of the local Fermi‐level position in the Si bandgap on B diffusivity, . It is shown that is linearly dependent on the free hole concentration, , over the range , where is the effective intrinsic electron concentration. This result does not depend on the way in which the background dopant has been introduced (implantation predeposition or doped‐oxide source), nor the type of dopant used (P or As).