Fabrication and photoluminescence of GaN/sapphire submicron-scale structures with nanometre scale resolution

We report the fabrication of submicon-scale structures using high resolution etching to transfer patterns from PMMA into GaN with an intermediate mask consisting of a bilayer of titanium and SiNx. Atomic force microscopy measurements showed the high quality of the structures etched in CH4/H2 as well as an erosion of the mask. The low temperature photoluminescence measured on the etched structures was almost as strong as that from the unetched surface.