Defect reduction mechanisms that were active during the growth of GaN by nano-hetero-epitaxy onto (00▪1) 6H-SiC. Nano-heteroepitaxial and planar GaN epitaxial films were grown and compared by using transmission electron microscopy, photoluminescence, X-ray diffraction, and time-resolved photoluminescence methods. It was found that, in addition to a previously reported defect reduction mechanism that resulted from the high compliance of nanoscale nuclei, other independent defect reduction mechanisms were also active during nano-hetero-epitaxy. These included the filtering of substrate defects, an improved coalescence at the nanoscale and defect termination at local free surfaces. It was also found that the biaxial strain in the GaN film could be significantly reduced by using a so-called grouped nano-heteroepitaxial pattern geometry.

Defect Reduction Mechanisms in the Nanohetero-Epitaxy of GaN on SiC. X.Y.Sun, R.Bommena, D.Burckel, A.Frauenglass, M.N.Fairchild, S.R.J.Brueck, G.A.Garrett, M.Wraback, S.D.Hersee: Journal of Applied Physics, 2004, 95[3], 1450-4