Dry etching of GaN using reactive ion beam etching and chemically assisted reactive ion beam etching

Abstract

Dry etching characteristics of GaN using reactive ion beam etching (RIBE) were studied. Etching profile, etching rate and etching selectivity to a photoresist (PR) mask were investigated as a function of various etching parameters. Characteristics of chemically assisted reactive ion beam etching (CARIBE) and RIBE were compared at varied mixtures of CH4 and Cl2. A highly anisotropic etching profile with a smooth surface was obtained for tilled RIBE with Cl2 at room temperature. Etching selectivity to a PR was dramatically improved in RIBE and CARIBE when a volume fraction of CH4 to the mixture of CH4 and Cl2 was larger than 0.83.