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Morphological evolution of Ge/Si(001) quantum dot rings formed at the rim of wet-etched pits

Martyna Grydlik*, Moritz Brehm and Friedrich Schäffler

Author Affiliations

Institut für Halbleiter-und Festkörperphysik, Johannes Kepler Universität, Altenbergerstr. 69, Linz, 4040, Austria

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Nanoscale Research Letters 2012, 7:601  doi:10.1186/1556-276X-7-601

Published: 30 October 2012


We demonstrate the formation of Ge quantum dots in ring-like arrangements around predefined {111}-faceted pits in the Si(001) substrate. We report on the complex morphological evolution of the single quantum dots contributing to the rings by means of atomic force microscopy and demonstrate that by careful adjustment of the epitaxial growth parameters, such rings containing densely squeezed islands can be grown with large spatial distances of up to 5 μm without additional nucleation of randomly distributed quantum dots between the rings.

SiGe; Quantum dots; Molecular beam epitaxy growth; Pit-patterned substrates