Coexistence of chalcopyrite and CuAu-type ordered structures in In0.52Al0.48As epilayers grown on InP substrates

摘要

Ordering formation in In0.52Al0.48As alloys grown on (00 1) InP substrates by metalorganic chemical vapor deposition was investigated using transmission electron microscopy (TEM). In the plan-view selective area diffraction pattern, the 12 superlattice reflections around the transmitted spot and the {2 0 0} spots were observed, which are associated with the chalcopyrite- and CuAu-type ordered structures. In the InAlAs consisting of III-III-V elements, these ordered phases with the rod-shaped domains elongated along the [2 2 0] show the coexistence of CuAu- and chalcopyrite-type ordered structures. An atomic model showing the formation process of the diffraction pattern of the chalcopyrite- and CuAu-type ordered structures is presented here based on the TEM results. (c) 2006 Published by Elsevier B.V.