Lateral-size control of trench-buried quantum wires using GaAs/AlAs superlattice layers

We demonstrated the lateral-size control of GaAs/AlAs trench-buried quantum wires (QWRs) in the region below 20 nm by using GaAs/AlAs superlattice layers (SLs). Scanning electron microscopy images and photoluminescence properties of the trench-buried QWRs revealed that the trench width can be controlled by varying the number of SLs and reduced to about 13 nm by growing 7 pairs of SLs. The GaAs wires in the trenches have a tendency to grow so as to maintain a constant cross-sectional area, which leads to reduction of the energetic broadening of the quantum sub-levels caused by pattern size fluctuation.