We compare directly the rates of bulk versus surface transport for Ni in and on Si(111) by depositing a laterally confined dot of Ni on one side of a double-polished and UHV cleaned Si wafer and then measuring the lateral Auger profile on the reverse side following annealing and quenching. Ni reaches the far side of the wafer at temperatures as low as 550°C via bulk diffusion with no measurable contribution from surface paths, which are short circuited by numerous, fast bulk paths. Similar results are found for Ni and Co on Si(111) and Si(100). Implications for silicide reactions in general are described.
ASJC Scopus subject areas
- Physics and Astronomy(all)