The crystalline structure of GaN grown by MOVPE on SiO2-stripe-patterned (111)Si, using AlGaN intermediate layer, was observed by transmission electron microscope for several growth stages. Islands growth of AlGaN occurred both in the window region and on the mask. But, only AlGaN in the window region serves as nucleation center for the GaN growth. These GaN islands occurred in the window region coalesce and form a stripe structure. Mainly observed defects in the GaN stripes are threading dislocations, which are generated by coalescence of GaN islands. Bending of the threading dislocations was observed.
