Abstract
High-density ordered triangular Si nanopillars with sharp tips and varied slopes were fabricated by reactive ion etching of ordered Ni nanodot arrays, patterned with nanosphere lithography, on silicon. The slope and aspect ratio of the nanopillars were controlled by variation of the mixing ratio of CF 4 and O 2 in the etching gas. Excellent field emission properties are attributed to the high density (9 × 10 8 cm -2 ), sharp (less than 10 nm) tips and well-controlled spacing between nanopillars so that the antenna effect is minimized. Sharp tips and a flared base, which are advantageous for a high field emission current and mechanical/thermal stability, respectively, can be tailor-made depending on the applications. © IOP Publishing Ltd.