Photo-Assisted Anodic Etching of Gallium Nitride Grown by MOCVD

Abstract

ABSTRACTIn this paper, the first study of photo-assisted anodic etching of unintentionally doped n-GaN at room temperature is reported. The electrolyte used is a mixture of buffered aqueous solution of tartaric acid and ethylene glycol. The etching rate varies from ∼20 Å/min to as high as 1600 Å/min. A systematic study shows that i) the etch rate, as well as the surface roughness, increases with the current density; ii) the etching rate is the highest when the pH of the electrolyte is around 7; iii) the etching is faster when there is more ethylene glycol in the electrolyte solution.