InSb Multiple Quantum Wells
The MQW structures are grown on GaAs (001) subtrates. There is a
14% lattice mismatch between GaAs and InSb. To compensate, an AlSb
nucleation layer is typically grown on the GaAs substrate.
AlSb has an 8.5% lattice mismatch with GaAs and a 6.1% mismatch with InSb.
The nucleation layer is followed by a thick buffer layer of
9% AlInSb whose lattice constant closely matches that of InSb,
which are 6.45 and 6.48 Å respectively.
Strain is initiated in the growing material due to the lattice mismatch
of the materials and is relieved through the production of dislocations.
The following section shows AFM images of InSb quantum well structures
and the associated dislocations.
(click on figure to expand)
Figure 1:
(a) Schematic diagram of InSb Multiple
Quantum well structure grown on GaAs. N refers to the number of wells
in the structure.
(b) InSb c(4x4) surface reconstruction.
|
|
