Nano Archive

Mechanism of the nanoscale localization of Ge quantum dot nucleation on focused ion beam templated Si(001) surfaces

Portavoce, A and Kammler, M and Hull, R and Reuter, MC and Ross, FM (2006) Mechanism of the nanoscale localization of Ge quantum dot nucleation on focused ion beam templated Si(001) surfaces. Nanotechnology, 17 (17). pp. 4451-4455. ISSN 09574484

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Official URL: http://dx.doi.org/10.1088/0957-4484/17/17/028

Abstract

We investigate the fundamental mechanism by which self-assembled Ge islands can be nucleated at specific sites on Si(001) using ultra-low-dose focused ion beam (FIB) pre-patterning. Island nucleation is controlled by a nanotopography that forms after the implantation of Ga ions during subsequent thermal annealing of the substrate. This nanotopography evolves during the annealing stage, changing from a nanoscale annular depression associated with each focused ion beam spot to a nanoscale pit, and eventually disappearing (planarizing). The correspondence of Ge quantum dot nucleation sites to the focused ion beam features requires a growth surface upon which the nanotopography is preserved. A further key observation is that the Ge wetting layer thickness is reduced in patterned regions, allowing the formation of islands on the templated regions without nucleation elsewhere. These results provide routes to the greatly enhanced design and control of quantum dot distributions and dimensions.

Item Type:Article
Subjects:Physical Science > Quantum phenomena
Analytical Science > Beam methods
ID Code:205
Deposited By:Lesley Tobin
Deposited On:18 Nov 2008 14:39
Last Modified:30 Jan 2009 16:52

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