Flux dependent 1.5 MeV self-ion beam-induced sputtering from gold nanostructured thin films

We discuss four important aspects of 1.5 MeV Au2+ ion-induced flux dependent sputtering from gold nanostructures (of an average size of approximate to 7.6 nm and height approximate to 6.9 nm) that are deposited on silicon substrates: (a) the Au sputtering yield at the ion flux of 6.3 x 10(12) ions cm(-2) s(-1) is found to be approximate to 312 atoms ion(-1), which is about five times the sputtering yield reported earlier under identical irradiation conditions at a lower beam flux of approximate to 10(9) ions cm(-2) s(-1), (b) the sputtered yield increases with increasing flux at a lower fluence and reduces at a higher fluence (1.0 x 10(15) ions cm(-2)) for nanostructured thin films while the sputtering yield increases with increasing flux and fluence for thick films (27.5 nm Au deposited on Si), (c) the size distribution of sputtered particles has been found to vary with the incident beam flux showing a bimodal distribution at a higher flux and (d) the decay exponent (delta) obtained from the size distributions of the sputtered particles showed an inverse power-law dependence ranging from 1.5 to 2.5 as a function of the incident beam flux. The exponent values have been compared with existing theoretical models to understand the underlying mechanism. The role of wafer temperature associated with the beam flux has been invoked for a qualitative understanding of the sputtering results in both the nanostructured thin films and thick films.