A simple wet etch for GaN

A simple UV photo-enhanced wet etch has been developed for GaN. Unlike phot oelectrochemical wet etching, this technique does not require an electrical contact to be made to the sample, and nitrides deposited on insulating sub strates (such as sapphire) can be etched. The technique relies on adding an appropriate oxidizing agent, in this case, peroxydisulfate to KOH solution s. Maximum etch rates are observed at pH 12.4. The etch rate increases line arly with Light intensity at 365 nm up to intensities of 25 mW/cm(2), where etch rates of up to 50 nm/min are observed.