The recrystallization of ion-implantedsilicon layers

Abstract
Rutherford backscattering and channeling (RBS) has been employed to investigate the annealing characteristics of ion-bombarded silicon for a wide range of implant species. The general recrystallization behaviour is that high levels of remnant disorder are observed for high-dose (typically > 1015 ions cm-2) implants of all species investigated, and transmission electron microscopy indicates the presence of a polycrystalline reordered layer in such cases. The magnitude of the remnant disorder (misorientation of grains with respect to the underlying bulk substrate) is observed to increase with both implant dose and original amorphous-layer thickness and to exhibit a slight implant-mass dependence. Although the recrystallization behaviour is qualitatively similar for all species studied, certain species (mainly those soluble in silicon) are found to influence the regrowth process at low implant concentrations. It is suggested that stress/strain effects, attributed to high implanted concentrations, play a major role in the inhibition of epitaxial silicon recrystallization but that species effects can become dominant at lower implant concentrations.