Epitaxial growth and characterization of nonpolar a-plane AlGaN films with MgN/AlGaN insertion layers

Abstract

MgN/AlGaN insertion layers were applied for the first time to the growth of nonpolar a-plane AlGaN epilayers by metal organic chemical vapor deposition technology. The full width at half maximum of the X-ray rocking curve for the a-plane AlGaN epilayers was reduced by approximately 50.6% and the root-mean-square roughness value of the surface was reduced by 74% by applying the MgN/AlGaN insertion layers with an optimized number of insertion pairs. These results reveal that the compressive strain within the a-plane AlGaN epilayers was effectively reduced, leading to significant improvements in crystalline quality and surface morphology. These improvements are very helpful in fabricating high-quality AlGaN-based ultraviolet light-emitting diodes.