An investigation was made of the room-temperature diffusion and trapping of implantation-generated point defects in crystalline samples. This was done by monitoring their interaction with dopants, native contaminants such as C or O, and other defects. Spreading resistance measurements showed that some 10-7 to 10-6 of the defects which were generated at the surface, by 40keV Si implantation, were injected into the bulk. These defects underwent trap-limited diffusion and produced dopant deactivation and/or partial annihilation of pre-existing -deep defect markers which had been produced by MeV He implantation. It was found that, in highly pure epitaxial layers, these effects extended to several microns from the surface, thus demonstrating the long-range migration of point defects at room temperature. More detailed analysis identified Si self-interstitials, injected into the bulk, as being the major cause of dopant deactivation and partial annealing of the vacancy-type defects (di-vacancies, P-vacancy, O-vacancy) which were generated by implantation. A lower limit of about 6 x 10-11cm2/s was deduced for the room temperature diffusivity of Si self-interstitials.

V.Privitera, S.Coffa, F.Priolo, L.K.Kyllesbech, S.Libertino, A.Carnera: Nuclear Instruments and Methods in Physics Research B, 1996, 120[1-4], 9-13