Stability of (1100) m-Plane GaN Films Grown by Metalorganic Chemical Vapor Deposition

We show the stability of planar nonpolar (1100) m-plane GaN thin films grown on m-plane 6H–SiC substrates using an AlN nucleation layer (NL) by metalorganic chemical vapor deposition (MOCVD). The stability of the m-plane GaN films was studied for a wide range of growth variables including reactor pressure, temperature, and group III and V flow rates. The surface morphology and crystal quality of the m-plane GaN films were less sensitive to changes in these growth variables than those of nonpolar (1120) a-plane heteroepitaxial planar GaN films. The threading dislocation density of m-GaN on m-plane 6H–SiC was one order of magnitude lower than that of a-GaN on a-plane 6H–SiC.