Fabrication of nanoporous GaN films with AAO masks and ICP etching

GaN films with nanopore arrays were fabricated by inductive coupled plasma（ICP） etching using anodic aluminum oxide（AAO） templates as mask.Nanoporous AAO templates were formed by evaporating Al films on GaN epilayers and then anodizing the Al films.Cl₂/Ar and Cl₂/He were employed as etching gas.Scanning electron microscopy（SEM） analysis shows that the nanoporous arrays can directly be transferred from AAO masks to GaN films in some proper conditions without any change in the pattern.Photoluminescence（PL） spectra and Raman spectroscopy were applied to assess optical and crystalline properties of nanoporous GaN films.This cost-effective,nonlithographic method to produce nano-patterned GaN templates is expected to be useful for fabrication of nitride-based nanostructures and photonic band gap materials.