Surface pretreatment and deposition temperature dependence of MgO epitaxy on GaN by thermal atomic layer deposition

Abstract

Abstract We report on the structural properties of MgO films deposited on GaN templates on sapphire substrates via atomic layer deposition (ALD). Analysis of the crystal quality and structure as a function of surface treatment and growth temperature are presented. Our results indicate deposition temperatures greater than 250 °C are preferable for achieving a high quality MgO thin film. Rotational scans of the samples show a six-fold symmetry at all deposition temperatures, indicating the existence of two rotational symmetric MgO crystal domains on the GaN surface, which were confirmed using electron backscatter diffraction.