| Autor: |
Krzyzewski, T.J., Jones, T.S. |
| Předmět: |
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| Zdroj: |
Journal of Applied Physics; 7/1/2004, Vol. 96 Issue 1, p668-674, 7p, 3 Black and White Photographs, 5 Graphs |
| Abstrakt: |
Scanning tunneling microscopy has been used to investigate the effects of annealing and quenching on InAs/GaAs(001) quantum dots (QD) grown at a low growth rate by molecular beam epitaxy (MBE). Significant changes in QD number density, average volume (of more than one order of magnitude), wetting layer morphology, and QD volume density have been observed after in situ annealing for up to 90 s at a growth temperature of 485 °C providing direct evidence for a QD ripening process resembling that observed in other heteroepitaxial growth systems. Inefficient sample removal from the growth chamber and cooling (quenching) leads to unintentional annealing and ripening of the QDs and/or the appearance of clusters on the sample surface. The appearance of these clusters can have a significant impact on any statistical analysis of QD samples. Our results show that MBE-grown InAs/GaAs(001) QDs are kinetically controlled structures even at low growth rates, and underline the importance of the quench method in minimizing postgrowth changes in the characteristics of the uncapped QD array and preserving the in situ surface morphology for ex situ surface studies. © 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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