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The study of
self-assembled nanostructures by Atomic Force Microscopy
O. BUTE, E. Placidi, F. Arciprete, F. Patella, M. Fanfoni, A.
Balzarotti, V. Cimpoca
Abstract. The aim of this article is to present a detailed Atomic Force
Microscopy study of InAs/GaAs (001) self-assembled quantum dots grown by
Molecular Beam Epitaxy during its complete evolution cycle (transition
from 2D islands to 3D islands). We have performed a statistical analysis
regarding the volume and density of QD, identifying the existence of two
separated distributions ( for quasi-3D dots and 3D dots). We have observed
that the density number value of quasi-3D QDs decreases from
1.1
X
1010 cm-2
to 4.3 X
109 cm-2
for a coverage between 1.57 ML and 1.61 ML, while for 3D QDs it increases
by a factor of 10 (from
2.1 X
1010 cm-2 to 2.3
X
1010 cm-2)
so as the 3D QDs become the prevailed structures. We can assume as
critical coverage, 1.59 ML. |