Novel aspects of the atomic transport of B implanted in silicon at energies below 1 keV

The non equilibrium diffusion of ultra-low energy B ions implanted into Si is characterized by an ultra-fast process, occurring during the ramp-up of the thermal process, and by a transient enhancement of the diffusion with an activation energy of 1.7 eV. We have also investigated the location of the defects causing the transient enhanced diffusion. The fast and ultrafast processes are found to be generated by defects located at different depths. The defects responsible for the fast tail shift are located closer to the surface than the defects leading to the ultrafast tail shift.