Journal of Crystal Growth, Vol.294, No.2, 168-173, 2006
Ordered InAs QDs using prepatterned substrates by monolithically integrated porous alumina
In this work, we explore a method for obtaining site-controlled InAs quantum dots (QDs) on large areas of GaAs (001) pre-patterned surface. The patterning of the substrate is obtained by using a monolithically integrated nano-channel alumina (NCA) mask and transferring its self-ordering to the underlying GaAs substrate by continuing the anodization process once the GaAs surface is reached. After patterning, the GaAs substrate follows a low temperature process for surface preparation before epitaxial growth for QD formation. As a final result, we observe that the nanoholes act as preferential nucleation sites for InAs QD formation, with a filling factor close to unity, while the QD formation on the surface region between the pattern holes is completely suppressed. (c) 2006 Elsevier B.V. All rights reserved.
Keywords:nanostructures;patterned substrates;molecular beam epitaxy;quantum dots;semiconducting III-IV materials