Self-organization of large-area periodic nanowire arrays by glancing incidence ion bombardment of CaF2(111) surfaces

The fabrication of well-ordered nanowire arrays over large areas is a challenge with many potential applications. Here we report a novel glancing incidence ion beam assisted self-organization approach to form periodic wire arrays over large areas on a CaF2(111) substrate. Preferential erosion of fluorine by the 4.5 keV Ar+ ion beam creates a surface enriched in calcium. The calcium self-organizes in elongated island structures of preferential width and separation. If the sample is irradiated along a fixed azimuth we observe nanowires with similar to 10 nm periodicity and wire lengths of at least several micrometers oriented along the azimuthal direction of ion beam incidence. Electrical conductivity measurements reveal an anisotropy in conductivity of at least three orders of magnitude. (C) 2001 American Vacuum Society.