Abstract
AlN epitaxial growth on 6H-SiC substrates with the (11
0) face, which is parallel to the <0001> direction, has been investigated. AlN epitaxial layers were grown by molecular-beam epitaxy (MBE) using elemental Al and rf plasma-excited nitrogen (N*). The surface roughness of the AlN layers was relatively small (rms roughness of 0.98 nm). From the results of reflection high-energy electron diffraction (RHEED), AlN layers on 6H-SiC (1120) substrates were revealed to be grown toward the [110] direction, not toward the [0001] direction. AlN and 6H-SiC (110) had an exact epitaxial relationship, i.e., [110]AlN∥[110]SiC and [0001]AlN∥[0001]SiC. The polytype of the AlN layer was also discussed based on the results of microscopic Raman scattering spectroscopy.