Biomedical Engineering Reference
In-Depth Information
Fig. 1.18
Nucleation of site-controlled single QDs (
a
) and QDs pairs (
b
) after epitaxial growth
into a “double structure” nanohole for samples without and with a 7-nm-thick GaAs buffer layer
growth, respectively. The profiles drawn on the nanoholes along the [1 1 0] and [1
−
1 0] directions
are shown at the
right
for single QDs (
c
) and QDs pairs (
d
)
Importantly, these results show that the number of QDs nucleated inside patterned
stripes can be controlled by simply varying the length of the initial oxide line along
the [1 1 0] direction, with no limitations in QDs number.
In the case of initial oxide dots with a “double structure,” single QDs (Fig.
1.18
a)
and QDs pairs with a peak-to-peak distance of 65
±
18 nm (Fig.
1.18
c) are obtained
in a reproducible way for samples without and with GaAs buffer layer growth. The
initial fabricated oxide structures are identical and therefore, the number of InAs
