Anomalous diffusion effects were observed when Ge was diffused with P, B, or As in inert or oxidizing ambients. The Ge, which was an unchanged column-IV dopant with a covalent radius that was close to that of Si, appeared to alter the point defect population in the Si lattice. During oxidation, the usual oxidation-enhanced diffusion was not observed when Ge was present in the lattice. The anomalous tail diffusion of high concentrations of P was also reduced when Ge was present.

J.R.Pfiester, P.B.Griffin: Applied Physics Letters, 1988, 52[6], 471-3