A GaN pyramid was grown selectively onto a (111)Si substrate, with a patterned dot structure, by means of metalorganic vapour phase epitaxy; and with AlGaN as an intermediate layer. The dot pattern consisted of an array of 5μm-diameter window openings with a 10μm period. The density of threading dislocations which was observed in the window region decreased gradually with increasing distance from the interface. This was due mainly to dislocation reactions and the bending of threading dislocations in the first 2μm from the interface. The predominantly observed defects in the lateral-growth part were dislocations parallel to the interface.

Defect Structure in Selective Area Growth GaN Pyramid on (111)Si Substrate S.Tanaka, Y.Kawaguchi, N.Sawaki, M.Hibino, K.Hiramatsu: Applied Physics Letters, 2000, 76[19], 2701-3