The transient diffusion of ion-implanted P under non-oxidizing conditions was studied for P doses of 7 x 1013 and 1015/cm2 at 20keV. Annealing (rapid thermal, or furnace) was carried out in N2 at 950 or 1050C. A kink was observed in secondary ion mass spectroscopy profiles after both types of annealing. Significant enhanced diffusion was observed for concentrations which were below the kink. It also appeared that P atoms in the surface region tended to pile up at the SiO2/Si interface. The P diffusion was modelled by using a published empirical model for B and As diffusion. A comparison of various simulations showed that P concentrations above the kink (P pile-up) were immobile. The P pile-up appeared to be active in high-dose samples, but inactive in low-dose samples. This behavior was attributed to the formation of some type of P-vacancy complex in the vacancy-rich region at the surface.

An Investigation of Phosphorus Transient Diffusion in Silicon Below the Solid Solubility Limit and at a Low Implant Energy. H.R.Soleimani: Journal of the Electrochemical Society, 1994, 141[8], 2182-8