Surface-charge lithography for GaN microstructuring based on photoelectrochemical etching techniques

摘要

We show that host defects introduced at the surface of GaN epilayers by mechanical means (e.g., using needles, microscribers), or 2-keV-argon ion beam are resistant to photoelectrochemical etching in aqueous solution of KOH, presumably due to trapped negative charge. The spatial distribution of surface defects and related negative charge can be designed as lithographic mask for the purpose of GaN microstructuring. The possibility to fabricate GaN mesostructures using the approach involved is demonstrated.