Characterization of Ar+ based Ion Beam Etching of GaN

In this paper the characterization of dry etching process of gallium nitride epitaxial layers with use of ion beam etching technique (IBE) is presented. Dry etching based patterning of GaN in experimental setup employing Ar⁺ ions as a milling medium is shortly described in the first part of the article. The parameters of the process, on which the overall etching efficiency i.e. gallium nitride etch rate and etching selectivity depends, were changed successively. Slow-rate etching mode for different Ar⁺ ion energies (400divide800 eV) and Ar⁺ ion beam angles of incidence (0degdivide60deg) was achieved in this experiment. The usability of IBE etching technique for structuring and optical devices fabrication in GaN is discussed, where the inclination of sidewalls and optical roughness of etched surface were taken as determining factors