The reactive ion beam etching (RIBE) of GaN and AlGaN/GaN using methane-based plasmas was investigated. Methane/hydrogen/argon gas mixture resulted in a rough etched GaN surface and severe N-depletion layer. The addition of nitrogen gas resulted in a smooth etched GaN surface with comparable rms roughness to the original one and in a lower etch rate. In addition, the near stoichiometric etched GaN surface was obtained. Photoluminescence study showed that the addition of nitrogen gas drastically improved the optical properties of the etched AlGaN/GaN heterostructures. Using the optimized etching condition, we successfully fabricated the AlGaN/GaN nanowire with the width of 110 nm.
展开▼
