Fabrication of uniform Au silicide islands on the Si(1 1 1)-(7 × 7) substrate

The Au silicide islands have been fabricated by additional deposition of Au on the prepared surface at 270 °C where the Si islands of magic sizes were formed on the Si(1 1 1)-(7 × 7) dimer-adatom-stacking fault substrate. The surface structure on the Au silicide islands shows the Au/Si(1 1 1)-√3 × √3 reconstructed structure although the substrate remains 7 × 7 DAS structure. The size of the Au silicide islands depends on the size distribution of the preformed Si islands, because the initial size and shape of the Si islands play important roles in the formation of the Au silicide island. We have achieved the fabrication of the Au silicide islands of about the same size (∼5 nm) and the same shape by controlling the initial Si growth and the additional Au growth conditions.