Ion induced segregation in gold nanostructured thin films on silicon

摘要

We report a direct observation of segregation of gold atoms to the near surface regime due to 1.5 MeV Au~(2+) ion impact on isolated gold nanostructures deposited on silicon. Irradiation at fiuences of 6 × 10~(13),1 × 10~(14) and 5 × 10~(14) ions cm~(-2) at a high beam flux of 6.3 × 10~(12) ions cm~(-2) s~(-1) show a maximum transported distance of gold atoms into the silicon substrate to be 60,45 and 23 nm, respectively. At a lower fluence (6 × 10~(13) ions cm~(-2)) transport has been found to be associated with the formation of gold silicide (Au_5Si_2). At a high fluence value of 5 × 10~(14) ions cm~(-2), disassociation of gold silicide and out-diffusion lead to the segregation of gold to defect - rich surface and interface regions.