Implanted B and P exhibit transient enhanced diffusion during initial annealing, due to Si interstitials which are emitted from regions of implantation damage. However, the source of these interstitials had not previously been identified. Here, quantitative transmission electron microscopy of extended defects was used to demonstrate that transient enhanced diffusion was caused by the emission of interstitials from specific defects. The defects were rod-like, ran along <110> directions, and consisted of interstitials which precipitated onto {311} planes as a single monolayer of hexagonal Si. The evaporation of {311} defects during annealing at 670 and 815C was correlated with the length of the diffusion transient, and it was demonstrated that there was a link between the numbers of interstitials which were emitted by the defects and the flux of interstitials which led to transient enhanced diffusion. It was concluded that not only did {311} defects contribute to the interstitial flux, but that a contribution which could be attributed to {311} defect evaporation was sufficient to explain all of the observed transient. The {311} defects were the source of the interstitials.

D.J.Eaglesham, P.A.Stolk, H.J.Gossmann, J.M.Poate: Applied Physics Letters, 1994, 65[18], 2305-7