Surface Characterization of GaN(0001) Grown by Liquid Phase Epitaxy Using Coaxial Impact-Collision Ion Scattering Spectroscopy

Abstract

We characterized the surface cleanliness, structure, and composition of GaN(0001) grown by liquid phase epitaxy (LPE) using coaxial impact-collision ion scattering spectroscopy (CAICISS). Contamination on the as-received LPE-GaN(0001) was removed by annealing at 900 °C, but annealing was unable to remove the O atoms from the as-grown surface, indicating that the as-grown sample incorporated O atoms. Although the as-grown sample contained O atoms, its structural perfection was maintained. These facts were explained by localization of O atoms near dislocations. The etched surface exhibited high crystalline quality, which was comparable to that of the sample grown by vapor phase epitaxy (VPE).