Uphill diffusion of ultra low energy boron implants in preamorphised silicon and silicon on insulator

Redistribution during annealing of low energy B implants in SOI and bulk Si has been investigated by comparing SIMS and simulated profiles. All the samples have been pre amorphized with Ge at different implantation energies in order to investigate the effects of the position of the damage on B diffusion. In our experimental conditions the amount of trapped B increases with reducing the depth of the amorphous layer and is higher in bulk Si than in SOI.