Au, Mg and Zn diffusion in GaN

Abstract

Transmission electron microscopy was used to study the defects generated in GaN heteroepitaxial layers during diffusion of Au, Zn and Mg in the temperature range 900°C – 1200°C. The diffusion annealings were carried out under N2 pressure of 1 GPa in oder to avoid decomposition of GaN. Diffusion of the metals into the GaN layers was connected with formation of voids and nanotubes along dislocation cores. Reasons and mechanisms of their formation were discussed. The penetration profiles were measured by means of SIMS. The effective diffusion coefficients and the activation energy for Au diffusion in GaN were calculated.