It was noted that the misfit between GaN and 6H-SiC was equal to 3.5%, instead of the 16% in the case of growth on sapphire. The misfit between AlN and 6H-SiC was only 1%. Therefore, the preparation of GaN on AlN/6H-SiC was expected to be a good route for the further improvement of the quality of ELOG GaN. The GaN was here grown on AlN in an early stage of coalescence in order to identify which dislocations bent, and why. It was found that the ELOG islands were always limited by {10▪0} facets. From the centres of these islands, more than 99% of dislocations bent to the basal plane. The a-type dislocations were found to fold many times, from basal to prismatic plane whereas, when a+c dislocations bent to the basal plane, they were not seen to come back to a prismatic one.

A TEM Evaluation of ELOG GaN Grown on AlN Buffer Layer by HVPE on (0001) 6H-SiC. P.Ruterana, B.Beaumont, P.Gibart, Y.Melnik: Physica Status Solidi B, 1999, 216[1], 697-700