Nickel silicidation on sulfur implanted Si(100)

Silicidation of Ni on sulfur implanted Si(100) substrates with different sulfur doses and nickel thicknesses was studied. The location of the NiSi/Si interface with respect to the implantation depth influences the silicide phase formation at a temperature window from 550degC to 700degC. As the NiSi/Si interface is deeper than the maximum implantation peak, NiSi is the dominant phase, independent of the S⁺ implantation dose. However, NiSi₂ is formed after silicidation with a thinner Ni layer on a high dose S⁺ implantation preamorphised Si substrate. High quality epitaxial NiSi₂ layers are grown in this case at higher temperatures. It is also found that the agglomeration of the NiSi layer results in a redistribution of the segregated S atoms at the NiSi/Si interface.