Capping process of InAs∕GaAs quantum dots studied by cross-sectional scanning tunneling microscopy
- 6 December 2004
- journal article
- research article
- Published by AIP Publishing in Applied Physics Letters
- Vol. 85 (23) , 5697-5699
- https://doi.org/10.1063/1.1831564
Abstract
The capping process of self-assembled InAs quantum dots (QDs) grown on GaAs(100) substrates by molecular-beam epitaxy is studied by cross-sectional scanning tunneling microscopy. GaAs capping at causes leveling of the QDs which is completely suppressed by decreasing the growth temperature to . At elevated temperature the QD leveling is driven in the initial stage of the GaAs capping process while it is quenched during continued overgrowth when the QDs become buried. For common GaAs growth rates, both phenomena take place on a similar time scale. Therefore, the size and shape of buried InAs QDs are determined by a delicate interplay between driving and quenching of the QD leveling during capping which is controlled by the GaAs growth rate and growth temperature.
Keywords
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