A transmission electron microscopic study was made of films which had been produced by using an epitaxial lateral overgrowth technique which involved SiO2-mask/windows, stripe-patterned GaN layers, and hydride vapor-phase epitaxy. The regions which were overgrown on SiO2 masks were carefully examined. Cross-sectional transmission electron microscopy clearly revealed the presence of characteristic defects along the [00•1] direction in the overgrown region. These consisted of arrays of dislocations which ran in the mask stripe direction. These defects caused a crystallographic tilting, in the region near to the mask, with respect to other regions grown from the window area. The vertical re-propagation of dislocations, which had propagated laterally during epitaxial lateral overgrowth, was also observed at the coalesced site on the mask.

A.Sakai, H.Sunakawa, A.Usui: Applied Physics Letters, 1998, 73[4], 481-3