hide
Free keywords:
Molecular-beam epitaxy; Surface; GaAs(2511); Islands
Abstract:
The shape of InAs quantum dots (QDs), grown by molecular-beam epitaxy on the GaAs(113)A surface, is studied by in situ scanning tunneling microscopy. At an early growth stage, the QDs adopt a shape given by {110}, (111)A, and {2 5 11}A bounding facets and an unresolved rounded {001} region. At a later growth stage, the QDs become elongated along [33 (2) over bar], with a reduction of the (111)A facet size and a flattening of the rounded region. This is explained by facet growth kinetics. The broad size distribution indicates growth limitation. The symmetry of the substrate is retained in the QDs, proving epitaxial growth.
