A route for the top-down fabrication of ordered ultrathin GaN nanowires.

We introduce a facile route for the top-down fabrication of ordered arrays of GaN nanowires with aspect ratios exceeding 10 and diameters below 20 nm. Highly uniform thin GaN nanowires are first obtained by lithographic patterning a bilayer Ni/SiNhard mask, followed by a combination of dry and wet etching in KOH. The SiNis found to work as an etch stop during wet etching, which eases reproducibility.