Published online by Cambridge University Press: 25 February 2011
Damage produced by 1.0-2.5 MeV self-ion and O-ion implantation into Si and Ge single crystals has been characterized by cross-sectional electron microscopy and ion channeling. In Si, it is observed that the damage morphology varies substantially along the ion's track. Near the end-of-range of the ion, damage accumulation is very similar to that which occurs during medium- to low-energy implantation (i.e., damage increases monotonically with dose until the lattice is made completely amorphous). In front of this end-of-range region, however, damage saturates at a very low level for moderate implantation fluences. A model based on homogeneous damage nucleation in Si is discussed. For Ge, damage accumulation is very different; a monotonic increase of damage with dose is observed over the entire range of the ion. Possible mechanisms responsible for the differences between Si and Ge are discussed.