It was recalled that end-of-range dislocations formed far from amorphizing implants if a critical amount of damage was present in the amorphous/crystalline transition region. The role of the substrate temperature and of the implantation energy in determining residual damage formation was investigated here. Implantation of 100keV Ge at room temperature and liquid-N temperatures, and ultra-shallow implantation of 20keV Ge or As and 5keV B at room temperature, were carried out using various doses above the amorphization threshold. The samples were then annealed at 200 to 900C. The numbers of displaced atoms which were located within the amorphous zones of the amorphous/crystalline transition region were determined from a Rutherford back-scattering channelling study of the low-temperature annealing behavior of the implanted samples. It was concluded that this number should be maximized in order to avoid dislocation formation. Plan-view transmission electron microscopy was used to analyze implanted samples after final annealing (900C, 0.25h). All of the ultra-shallow implanted samples were found to be dislocation-free.

S.Acco, J.S.Custer, F.W.Saris: Materials Science and Engineering B, 1995, 34[2-3], 168-74