Using the vapour-liquid-solid method with separated 220nm-thick Au catalyst circles/stripes configurations sputtered onto GaAs substrate surface, an investigation was made of the effects of Au droplet/cluster formation as well as the nanowire growth process inside and outside the Au circle/stripe configurations. The Au surface outward diffusion from the Au layer edge up to several tens of micrometers was strongly dominant. The effects of Au surface diffusion on the formation of Au droplets/cluster and on nanowire growth on GaAs substrate in the region outside the Au layers were shown. The mechanism of the droplets/clusters formation outside the Au layer could be explained by the surface cluster diffusion, meanwhile the nanowires had grown simultaneously during the Au outwarddiffusion. The growth could be explained by the diffusion of Ga and As atoms into the diffusing Au droplets/clusters, via a dissociative mechanism, to form nanowire seeds inside for nanowires growth. The Au droplet/cluster formation and nanowire growth on the GaAs substrate outside Au layer could be applied to making nanodevices blocks outside the Au layer. This Au surface diffusion phenomenon could also cause short-circuit;, even at thin Au layers.

The Effects of Au Surface Diffusion to Formation of Au Droplets/Clusters and Nanowire Growth on GaAs Substrate using VLS Method. K.A.Dao, D.K.Dao, T.D.Nguyen, A.T.Phan, H.M.Do: Journal of Materials Science - Materials in Electronics, 2012, 23[11], 2065-74