Directed self-assembly of quantum structures by nanomechanical stamping using probe tips

Curtis Taylor, Department of Mechanical Engineering, Virginia Commonwealth University
Euclydes Marega, Department of Physics, University of Sao Paulo
E A. Stach, Birck Nanotechnology Center and School of Materials Engineering, Purdue University
Gregory Salamo, Department of Physics, University of Arkansas
Lindsay Hussey, Department of Physics, University of South Florida
Martin Muñoz, Department of Physics, University of South Florida
Ajay Malshe, Department of Mechanical Engineering, University of Arkansas

Abstract

We demonstrate that nanomechanically stamped substrates can be used as templates to pattern and direct the self-assembly of epitaxial quantum structures such as quantum dots. Diamond probe tips are used to indent or stamp the surface of GaAs( 100) to create nanoscale volumes of dislocation-mediated deformation, which alter the growth surface strain. These strained sites act to bias nucleation, hence allowing for selective growth of InAs quantum dots. Patterns of quantum dots are observed to form above the underlying nanostamped template. The strain state of the patterned structures is characterized by micro-Raman spectroscopy. The potential of using nanoprobe tips as a quantum dot nanofabrication technology are discussed.