Abstract
The correlation between surface morphology and interface properties of (Al, Ga)As quantum wells (Qwell) grown by molecular-beam epitaxy on GaAs (100) and patterned GaAs (311)Ga substrates is investigated by atomic force and scanning electron microscopy in comparison with spectrally and spatially resolved cathodoluminescence (CL), as well as micro-photoluminescence spectroscopy. On unpatterned GaAs (100) substrates, both the surfaces and Qwell interfaces exhibit at least two roughness components with correlation length on a nanometer and micrometer scale. On GaAs (311)Ga substrates patterned with mesastripes along the [011] direction, one side of the mesastripe develops a fast-growing, convex sidewall with thicker Qwell regions below, which are suitable to act as quantum wires. For a zigzag-shaped mesastripe, the growth results in wire branches with dotlike regions between them. The latter are electronically coupled with the wire branches.