Anisotropic growth of nanostructures in germanium electroplating

An anisotropic growth of nanostructures was observed when germanium was electroplated on a patterned silicon substrate from a nonaqueous solution. Instead of an isotropic growth of mushroom cap expected for electroplating through mask, wire-shaped and wall-shaped structures were obtained, respectively, on via and stripe patterns on silicon substrate. The presence of water in the electrolyte and a high current density were found critical to the anisotropic growth. A passivation of outer surface of the deposit is believed to be involved and prohibits the lateral growth of the deposit. © 2007 The Electrochemical Society.