Segregation of ion implanted sulfur in Si(100) after annealing and nickel silicidation

Diffusion of sulfur (S) in S+ ion implanted Si(100) was investigated after rapid thermal annealing as well as after nickel silicidation. At lower S doses, S segregates to the Si(100) surface when the defects created by the S implantation are reduced during annealing. If the S dose exceeds the amorphization threshold, two heavily damaged regions with dislocation loops appear after annealing. It seems that S atoms form stable complexes with dislocation loops that survive even after high-temperature anneals at 900 °C. In contrast, when silicidation comes into play, S atoms appear more mobile. Even during Ni silicidation at 550 °C, segregation yields an enrichment of S at the NiSi/Si interface while the defect density and the S content in the deeper Si regions decrease.