Lattice location of implanted Co in heavily doped n+- and p+-type silicon

© 2017, Springer-Verlag Berlin Heidelberg. We have studied the influence of electronic doping on the preferred lattice sites of implanted 61 Co , and the related stabilities against thermal annealing, in silicon. Using the β - emission channeling technique we have identified Co on ideal substitutional (ideal S) sites, sites displaced from bond-centered towards substitutional (near-BC) sites and sites displaced from tetrahedral interstitial towards anti-bonding (near-T) sites. We show clearly that the fractions of Co on these lattice sites change with doping. While near-BC sites prevail in n + -type Si, near-T sites are preferred in p + -type Si. Less than ∼ 35% of Co occupies ideal S sites in both types of heavily doped silicon, showing that the majority of implanted Co forms complex defect structures. Implantation-induced defects seem to getter more efficiently Co in lightly doped n-type than in heavily doped n + - or p + -type silicon. The formation of CoB pairs in p + -type silicon and its possible influence on the lattice sites is discussed.status: publishe