EFFECTS OF ANNEALING ON DOPED AND UNDOPED ION-BEAM SYNTHESIZED COSI2 STRUCTURES

The effects of implanting Sb into as implanted and annealed ion beam s ynthesised (IBS) CoSi2 layers and their subsequent behaviour during se quential isochronal annealing is investigated. For both the as implant ed and annealed samples there is some Sb diffusion, towards the CoSi2 interfaces, during annealing. The extent of this diffusion is greater for the as implanted sample than for that which was annealed at 600 de grees C/1 h+1000 degrees C/30 min prior to Sb implantation. During seq uential annealing the Sb initially moves onto substitutional sites (be low 400 degrees C). However, once it starts to diffuse, it is found pr edominantly on interstitial sites. After annealing at 1000 degrees C t he crystal quality of the Sb doped layers is similar, if not superior, to that found in undoped layers, indicating that the damage introduce d during the Sb implant has been entirely removed. In addition, fewer defects are observed in the silicon adjacent to the lower CoSi2/Si int erface in the Sb implanted samples.