Evolution of Surface Morphology by Wet-Etching of ZnO and GaN with Different Polarity

摘要

The surface morphologies of ZnO and GaN thin film by wet-chemical etching were investigated. While ZnO was readily etched by acidic solutions regardless of its polarity, GaN was hardly etched by acidic solutions, but etched in alkali-based solutions such as KOH, especially for N-face GaN. Furthermore, we will also discuss the micro-structural evolution of hexagonal pyramids on the O-polar (N-polar) surfaces and hexagonal pits on the Zn-polar (Ga-polar) surfaces of ZnO and GaN, respectively.