Metalorganic vapor phase epitaxy growth of m-plane GaN using LiAlO2 substrates

The crystalline, surface, and optical properties of the m-plane GaN layer,town on the LiAlO2 (LAO) substrate by metalorganic vapor phase epitaxy (MOVPE) were demonstrated. The low temperature growth of the GaN buffer layer, performed in the nitrogen ambient, could lead to the smooth surface morphology. Because of the small lattice mismatch between GaN and the LAO substrate, the low-density line-shaped defects, possibly originated from stacking faults, were observed. In addition, high phase purity of the in-plane GaN epilayer was shown in the high resolution X-ray diffraction (HRXRD) spectrum. The different behavior was found for donor-bound exciton ((DX)-X-0) and defect-related transitions, characterized by the temperature-dependent photoluminescence (PL) measurement. These results suggest that the nitridation process and low temperature growth of the GaN buffer layer under nitrogen ambient could be suitable for realizing smooth and high phase purity m-plane GaN on LAO substrates.