Structural characterization of self-assembled InAs quantum dots grown by MBE

Molecular-beam epitaxy grown self-assembled InAs quantum dots: (QDs) have b een investigated by means of grazing incidence X-ray techniques. We reveal that the lateral distribution of InAs QDs is anistropic and the most pronou nced ordering of dot distribution is in [1 1 0] direction. Moreover, we det ermine the dot shape to be an octagonal-based truncated pyramid with {1 1 1 } and {1 0 1} Facet families. We also find that the strain is elastically r elated with different components when dots are formed. The volume distribut ion of partially strained InAs inside QDs is peaked at intermediate strain values. In addition, a small volume fraction of relaxed InxGa1-xAs is found . (C) 2001 Elsevier Science B.V. All rights reserved.