The role which was played by low-temperature deposited interlayers, inserted between high-temperature grown GaN layers during the organometallic vapor phase epitaxial growth of GaN on sapphire, was investigated by using in situ stress measurement, X-ray diffraction, and transmission electron microscopy. The insertion of a series of low-temperature GaN interlayers reduced the density of threading dislocations while simultaneously increasing the tensile stress during growth.

Stress and Defect Control in GaN using Low-Temperature Interlayers. H.Amano, M.Iwaya, T.Kashima, M.Katsuragawa, I.Akasaki, J.Han, S.Hearne, J.A.Floro, E.Chason, J.Figiel: Japanese Journal of Applied Physics - 2, 1998, 37[12B], L1540-2