Enhanced diffusion during the implantation of arsenic in silicon

The ``tail'' that is observed on the arsenic carrier profile formed by the implantation of arsenic in silicon is shown to be due to enhanced diffusion during implantation. The position of the tail is unaffected by postimplant annealing at temperatures up to 1000 °C. The arsenic ions comprising the tail are electrically inactive after implantation, and temperatures in excess of 700 °C are required to achieve complete activation. While the nature of the migrating species is unclear at this time, the results are consistent with an interstitial mechanism.