Formation of graphite nanocones using metal nanoparticles as plasma etching masks

Arrays of graphite nanocones were fabricated by plasma etching of highly oriented pyrolytic graphite (HOPG). Gold nanoparticles, which were used as etching masks, were deposited by immersing HOPG into colloidal gold solution. The shapes and sizes of fabricated nanopillars depended on the plasma etching parameters such as plasma gas, plasma power, and etching time; the choice of plasma gas was important for graphite-nanostructure fabrication in particular. The emission from the pillars fabricated using the oxygen plasma was turned on at 2.3 V//spl mu/m, and the emission current density as large as 35 mA/cm/sup 2/ was measured.