Fabrication of Flat End Mirror Etched by Focused Ion Beam for GaN-Based Blue-Green Laser Diode

Abstract

Heteroepitaxial GaN film was deposited on sapphire by metalorganic chemical vapor deposition. An end mirror for the GaN-based blue-green laser diode was prepared using focused ion beam (FIB) etching. The tilt angle normal to the GaN layer was shown to be less than 1° by scanning ion microscopy. The root mean square surface roughness was 11 Å as observed by atomic force microscopy. The data indicates that FIB is a powerful technique for the fabrication of GaN-based blue-green laser diodes.