Defect formation in AlN thin films that been grown onto (00•1) substrates 6H-type SiC was investigated, for film thicknesses of up to 180nm, by using conventional and high-resolution transmission electron microscopy. It was found that the presence of certain Si-terminated steps on the vicinal 6H-SiC surface led to the introduction of planar defects during the initial stages of growth. Films which had been deposited onto the on-axis substrate exhibited a much lower defect density. Atomistic structural models of the interface and of the deposited AlN were proposed on the basis of high-resolution transmission electron microscopy images and the results of scanning tunnelling microscopic studies of the vicinal (00•1) 6H-SiC surface. The introduction of additional defects (mainly threading dislocations) was observed with increasing thickness of the AlN films.

S.Tanaka, R.S.Kern, J.Bentley, R.F.Davis: Japanese Journal of Applied Physics, 1996, 35[1-3], 1641-7