MBE Growth of GaN on NdGaO3 (101)

We report on the growth of GaN on NdGaO3 (101) by plasma assisted molecular beam epitaxy (MBE). NdGaO3 (101) is an interesting alternative substrate compared to A12O3 due to its smaller lattice mismatch of +1.2 % to hexagonal (0001) GaN. Using photoluminescence (PL), X-ray diffraction (XRD), reflection high energy electron diffraction (RHEED) and atomic force microscopy (AFM) the optical and structural properties of the GaN thin films grown on NdGaO3 are investigated and compared to those grown on c-plane sapphire. The intended epitaxial relationship of [0001] GaN ║ [101] GaN is hard to realise as confirmed by several tilted or even polycrystalline films. However, the layer quality was found to improve considerably, when the NdGaO3 surface showed a (l × 1) instead of other reconstructions.