Effects of annealing on doped and undoped ion beam synthesised CoSi 2 structures

Abstract

The effects of implanting Sb into as implanted and annealed ion beam synthesised (IBS) CoSi 2 layers and their subsequent behaviour during sequential isochronal annealing is investigated. For both the as implanted and annealed samples there is some Sb diffusion, towards the CoSi 2 interfaces, during annealing. The extent of this diffusion is greater for the as implanted sample than for that which was annealed at 600°C/1 h + 1000°C/30 min prior to Sb implantation. During sequential annealing the Sb initially moves onto substitutional sites (below 400°C). However, once it starts to diffuse, it is found predominantly on interstitial sites. After annealing at 1000°C the crystal quality of the Sb doped layers is similar, if not superior, to that found in undoped layers, indicating that the damage introduced during the Sb implant has been entirely removed. In addition, fewer defects are observed in the silicon adjacent to the lower CoSi 2/Si interface in the Sb implanted samples.