Structural study of InAs quantum boxes grown by molecular beam epitaxy on a (001) GaAs-on-Si substrate

Abstract

InAs quantum boxes have been obtained by molecular beam epitaxy on a GaAs-on-Si substrate using the strained-induced 2D–3D transition. The boxes are examined by transmission electron microscopy and compared with those obtained under the same growth conditions on a GaAs substrate. Although there exist 107 dislocations per cm2 in the GaAs-on-Si substrate, high quality coherent strained islands are observed with a density slightly higher than on GaAs substrate. The behavior of the threading dislocations originating from the Si–GaAs interface when they cross the island plane is also investigated. Although some dislocations are bent in the island plane, the island distribution is apparently not affected by the vicinity of a threading dislocation.