I. Matsuyama et al., CATHODOLUMINESCENCE OF WIRE-LIKE GAAS ALAS QUANTUM-WELL STRUCTURES GROWN ON SUBSTRATES PATTERNED WITH (001) MESA STRIPES, JPN J A P 2, 33(5A), 1994, pp. 120000627-120000630
We describe cathodoluminescence (CL) spectroscopy and imaging studies
of GaAs/AlAs quantum well (QW) structures and AlGaAs alloys grown by m
olecular beam epitaxy on GaAs (100) substrates patterned with mesa str
ipes along the [001] direction. GaAs wirelike structures were formed o
n these mesas due to the large diffusibility of Ga atoms from the {110
} sidewalls to the (100) mesa-top plane. The spatial variation of the
QW thickness and that of an AlGaAs alloy composition were investigated
by carrying out CL measurements at low temperature. On the mesa-top r
egion we found considerably large variations in the QW thickness and A
l content, i.e., a 110% increase in the QW thickness and a 60% decreas
e in Al content, compared to the (100) bottom region. This is very use
ful for the fabrication of quantum-wire/box structures; thus, the use
of the [001] mesa geometry is advantageous over other geometries.