The dose-dependence of as-implanted damage, and the density of threading dislocations after MeV implantation, were measured. The role of damage and amorphization in the evolution of dislocation microstructures was considered. As-implanted damage was analyzed by means of Rutherford back-scattering spectroscopy and channelling. Etching was used to reveal threading dislocations in the near-surface regions of annealed (900C, 0.5h) samples. After various implants (600keV B, 1MeV P, 2MeV As) with a 1.1μm projected range, a sharp onset for the formation of threading dislocations was observed; with a peak in the dislocation density at a dose of about 1014/cm2. This dose depended upon the ion mass. The dislocation density decreased with a further increase in dose. This decrease was markedly different for the various ions. There was a sharp (4 to 5 orders of magnitude) reduction for P and As implants, and a slow decline for B implants. The sharp decrease in the density of threading dislocations at higher doses was related to the onset of amorphization which was observed for P and As implants. The data for low-temperature implants proved that a reduction in the dislocation density, for P and As implants, was the result of amorphization.

The Effect of As-Implanted Damage on the Microstructure of Threading Dislocations in MeV Implanted Silicon K.K.Bourdelle, D.J.Eaglesham, D.C.Jacobson, J.M.Poate: Journal of Applied Physics, 1999, 86[3], 1221-5