Biomedical Engineering Reference
In-Depth Information
c
a
b
InAs
Ga
InAs
GaAs (001)
GaAs (001)
GaAs (001)
As
4
Ga
As
4
Ga
As
4
GaAs
AsBr
3
In
As
4
In
As
4
In
As
4
In
As
4
As
4
In
d
e
InAs
InAs
150-nm
In
0.15
Ga
0.85
As
GaAs
InGaAs
superlattice
GaAs (311)B
GaAs (001)
Fig. 3.1
Growth process and evolution schematics of lateral QDMs grown on various templates:
(
a
) nanohole, (
b
) nanomound, and (
c
) nanohole-and-mound. Schematic cross-sectional structures
of lateral QDMs formed on (
d
) InGaAs/GaAs-(3 1 1)B superlattice and (
e
) InGaAs/GaAs-(0 0 1)
cross-hatch pattern templates
and coupling control. Most procedures reported so far are based on InGaAs/GaAs
systems using some kinds of templates and employ standard (0 0 1)-GaAs substrates
as summarized in Fig.
3.1
and described below.
3.2.1
QDMs on Nanohole Templates
This procedure was first reported by Songmuang et al. in 2003 [
10
]andshown
in Fig.
3.1
a. The first step is the formation of standard InAs QDs on a flat GaAs
substrate. The seed QDs are then capped with 10-nm GaAs, resulting in QDs