Local nanostructuring of gold thin films through dewetting induced by Ga+ irradiation

• Published in: Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms Vol. 354; pp. 129 - 133
• Main Authors: Lo Savio, R., Repetto, L., Šetina Batič, B., Firpo, G., Valbusa, U.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.07.2015
• Subjects: Beam interactions; Dewetting; Gallium; Gold; Ion irradiation; Irradiation; Nanoparticles; Nanostructure; Thin films; Nanoparticles; Thin films; Gold; Ion irradiation; Dewetting
• ISSN: 0168-583X; 1872-9584
• DOI: 10.1016/j.nimb.2014.11.057

Dewetting of ion-irradiated metal films is a consequence of the local melting occurring during the irradiation. In this study we present the dewetting evolution of Au thin films bombarded with Ga+ ions in a focused ion beam system, pointing out the different surface patterns observed in films having different starting thickness and morphology. In fact, in ion-irradiated films thicker than 2nm the typical features of dewetted liquids appear, i.e. enlarging dry holes surrounded by metal interconnections. On the other side, a different behavior is observed in thinner discontinuous films, where a dense distribution of circular nanoparticles is formed upon irradiation. We studied the dependence of Au nanoparticles distribution obtained for different ion energies and fluences, determining that a maximum fluence of ∼2×1014Ga/cm2 can be used to achieve a monomodal distribution of nanoparticles with regular shape, before detrimental effects of sputtering occur.