Self assembled patterns of gold nanoclusters in silicon (100) produced by metal vapour vacuum arc ion implantation

Self assembled gold nanoclusters are attractive building blocks for future nanoscale sensors and optical devices due to their exciting catalytic properties. Recently several methods have been employed to produce nanoclusters on solid substrates, which result in a random spatial distribution of the clusters. In this work, we have achieved ordered circular patterns of gold nanoclusters in Silicon (100) substrates by Au ion implantation followed by thermal annealing. This unique phenomenon is observed only above a critical threshold implantation dose and annealing temperature. Based on a systematic study (SEM, XTEM and XRD) of the growth and morphology of the nanoclusters, we propose a tentative model for the formation mechanism of this unusual self-assembled pattern.