STRUCTURAL STUDY OF INAS QUANTUM BOXES GROWN BY MOLECULAR-BEAM EPITAXY ON A (001)GAAS-ON-SI SUBSTRATE

InAs quantum boxes have been obtained by molecular beam epitaxy on a G aAs-on-Si substrate using the strained-induced 2D-3D transition. The b oxes are examined by transmission electron microscopy and compared wit h those obtained under- the same growth conditions on a GaAs substrate . Although there exist 10(7) dislocations per cm(2) 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 th reading dislocations originating from the Si-GaAs interface when they cross the island plane is also investigated. Although some dislocation s are bent in the island plane, the island distribution is apparently not affected by the vicinity of a threading dislocation. (C) 1997 Amer ican Institute of Physics.