Nanoscale pattern formation in Pt thin films due to ion-beam-induced dewetting

Abstract

Atomic force microscopy is used to characterize the evolution of film morphology produced by heavy-ion bombardment. Pt films, 3 and 5 nm thick, are deposited on SiO2 substrates and subsequently bombarded by 800 keV Kr+. Ion doses of >2×1014 initiate pattern formation and the dewetting of Pt films from the substrate. The film morphology becomes increasingly disconnected with increasing dose; at the highest doses, (∼2×1016 cm−2), isolated nanoparticles are formed with a uniform spacing. The results are explained by the nucleation of bare substrate patches and subsequent coarsening of the morphology by the molten zones created by individual Kr+ impacts.