Application of atomic-force-microscope direct patterning to selective positioning of InAs quantum dots on GaAs

Abstract

The application of atomic-force-microscope (AFM) direct patterning to the selective positioning of InAs quantum dots (QDs) on a (100) GaAs substrate has been proposed and experimentally implemented. The AFM direct patterning was used to generate various patterns of several tens of nanometers in size, and InAs QDs were subsequently grown by a metalorganic chemical vapor deposition technique. A nonuniform distribution of the QDs was observed near the patterns. The detailed shape of the QD distribution and the size of the QDs depended on the geometrical properties such as the sidewall angle, the spacing, and the width of the patterns. We have been able to ascertain, through our work, what growth conditions are necessary for QDs’ alignment along the patterns.

Early stages of mechanical deformation in indium phosphide with the zinc blende structure

“…Surface patterns involving the introduction of dislocations by nanoindentation, using standard and atomic force microscopy (AFM) techniques, have been used in order to determine the nucleation site of quantum dots and nanocrystals. [7][8][9][10] It is therefore important to investigate the details of the early stages of nanoscale mechanical deformation in cubic semiconductors.…”

Growth of linearly ordered arrays of InAs nanocrystals on scratched InP

“…InAs quantum dots have also been grown on GaAs substrates on pits and trenches produced by atomic force microscopy ͑AFM͒, where growth depended on the surface geometry. 10 Localized strain in combination with appropriate deposition kinetics has been used to induce site-selective nucleation of semiconductor nanostructures. [11][12][13] Selective epitaxial growth of Ge dots on Si substrates patterned with SiO 2 films was reported by Kim et al, 14 suggesting that nucleation of crystallites is influenced by strain and kinetics.…”

InP patterning using contact mode and non-contact AFM lithography for quantum dot localization

“…Coupling the latter with the Stranski-Krastanov growth mode [5] (well-known to provide high quality quantum dots) then allows for great improvement in QD characteristics such as narrow size distribution and controlled densities. Moreover, it permits an accurate control of QD spatial localization [6].…”