Growth of high-quality non-polar AlN on 4H-SiC(11-20) substrate by molecular-beam epitaxy

摘要

Non-polar AlN epitaxial growth on SiC substrates with the (11-20) face, which is parallel to the < 0001 > direction, has been investigated. AlN(11-20) epilayers were grown on 6H- and 4H-SiC(11-20) substrates by molecular-beam epitaxy (MBE) using elemental Al and rf plasma-excited nitrogen. The crystalline structure of the AlN layer was strongly influenced by the stacking structure of the SiC substrate. A considerably smooth AlN(11-20) layer with an rms roughness of 0.3 nm was obtained on the 4H-SiC(11-20) substrate. From the results of X-ray diffraction (XRD), the superior crystalline quality of the AlN(11 -20) layer on the 4H-SiC(11-20) substrate was clearly shown.