Properties of InN layers grown on 6H-SiC(0001) by plasma-assisted molecular beam epitaxy

We study the impact of different buffer layers and growth conditions on the properties of InN layers grown on 6H-SiC(0001) by plasma-assisted molecular beam epitaxy. Both GaN and AlN buffer layers result in a significant improvement of the structural quality compared to InN layers grown directly on the SiC substrate. However, to obtain layers exhibiting a high structural integrity, smooth surface morphology, high mobility and strong band-to-band photoluminescence, contradicting growth conditions are found to be required. Furthermore, since InN(0001) dissociates already at temperatures below the onset of In desorption, it is difficult to avoid In accumulation and inclusions of crystalline In in the layer under In-rich conditions. (C) 2004 American Institute of Physics.