Molecular-beam epitaxial growth of one-dimensional rows of InAs quantum dots on nanoscale-patterned GaAs

Single-dot-wide rows of InAs quantum dots (QDs) aligned along a [011̄] direction on a 180-nm-period nanoscale-patterned (nanopatterned) GaAs(100) substrate are reported. The nanopatterned substrate is realized by interferometric lithography along with the selective growth mode of GaAs. Orientation-dependent migration and incorporation of In atoms from (111)A to (100) facets on the nanopatterned substrate localizes QD formation exclusively along a 30–40-nm-wide (100) facet defined by neighboring (111)A-type facets within each period. These aligned QDs form face-to-face multi-QDs analogous to multi-quantum-well structures, in a one-dimensional configuration. Spatially controlled formation of QDs with an improved size uniformity on the nanopatterned substrate is presented.