Berlin 2008 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 18: Poster Session I - MA 141/144 (Atomic Wires; Size-Selected Clusters; Nanostructures; Metal Substrates: Clean Surfaces+Adsorption of Organic / Bio Molecules+Solid-Liquid Interfaces+Adsorption of O and/or H; Surface or Interface Magnetism; Oxides and Insulators: Clean Surfaces)
O 18.69: Poster
Montag, 25. Februar 2008, 18:30–19:30, Poster F
In-situ Etching of self-organized InAs/GaAs (001) Quantum Dots — •Theresa Lutz1, Takayuki Suzuki1, Lijuan Wang1, Suwit Kiravittaya1, Armando Rastelli2, Oliver G. Schmidt2, Giovanni Costantini1, and Klaus Kern1,3 — 1Max Planck Institute for Solid State Research, Stuttgart — 2Leibniz Institute for Solid State and Materials Research, Dresden — 3Ecole Polytechnique Fédérale de Lausanne, Switzerland
It is well known that the epitaxial growth of InAs on GaAs(001) leads to the development of strain induced nanoscale islands with high crystalline quality. Because of the enormous potential for device applications there is a great interest in understanding the growth process in detail. Even though there are a lot of experimental results concerning the growth of quantum dots, the physics behind it is not completely understood yet. Recently, it has been shown that during growth a transition takes place from small shallow faceted pyramidal islands to bigger and steeper islands, so-called domes. We use selective InAs in-situ etching to systematically modify the island size. The result is a backward transition of the islands as a function of the etching time. The details of the shape transition are discussed taking into account the non-uniform composition of the islands. This demonstrates that the shape of the quantum dots depends on their size and composition, which is typical for processes close to thermodynamic equilibrium.