Ordered silicon nanowire arrays via nanosphere lithography and metal-induced etching

Two-dimensional silica colloidal crystal template is used to create metal nanohole arrays on a silicon surface, which enables the controlled fabrication of aligned silicon nanowire (SiNW) arrays via metal catalytic etching. By varying the size of silica colloidal crystals, aligned arrays of SiNWs with desirable diameter and density could be obtained. The formation of ordered SiNW arrays is due to selective and anisotropic etching of silicon induced by the silver pattern. The orientation of SiNW arrays is influenced by silver movement in silicon, and the wire axes are primarily along the ⟨100⟩ direction.