Fabrication and properties of etched GaN nanorods

Gallium nitride nanorod arrays have been created via dry etching in Cl2/Ar plasma using a Ni mask formed by nanoimprint lithography and lift-off. Aspect ratios greater than 20 are demonstrated by optimizing the etch conditions to achieve near-vertical sidewalls. Such top-down etched nanorod arrays have greater uniformity when compared to bottom-up arrays, with the process already having been demonstrated on 4-inch wafers. (© 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)