Berlin 2008 – wissenschaftliches Programm
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DS: Fachverband Dünne Schichten
DS 42: Layer Growth: Evolution of Structure and Simulation
DS 42.3: Vortrag
Freitag, 29. Februar 2008, 16:45–17:00, H 2032
Monitoring quantum dot growth by in-situ cantilever systems — •yan wang1,2, huiling duan1,2, and joerg weissmueller1,3 — 1Institute of Nanotechnology, Forschungszentrum Karlsruhe, Postbox 3640, Karlsruhe, 76021, Germany — 2College of Engineering, Peking University, Beijing, 100871, P. R. China — 3Technische Physik Universität des Saarlandes, 66041 Saarbruecken, Germany
There exist many theoretical and experimental works that focus on understanding the growth mechanisms of quantum dots (QDs). Without an in-situ measurement technique that monitors the growth modes of QDs such as the Frank-van der Merwe (FM), the Volmer-Weber (VW), the Stranski-Krastanow (SK) growth modes, and their corresponding ripening states during deposition, it is difficult to make conclusions on the growth mechanisms and on the ripening mechanisms of QDs. To monitor the growth modes, QDs are located on a MBE chamber equipped with an in-situ cantilever measurement setup, and this cantilever is used as a substrate of QD growth.
In this paper, based on continuum models, we investigate a series of problems related to the strained heteroepitaxial in-situ cantilever systems of QD growth.We first obtain the curvature of this cantilever system, which provides a way to monitor the possible growth modes (FM, VW, SK and their corresponding ripening states) in terms of island density, wetting layer thickness and cantilever thickness, etc. Then, we give the equilibrium conditions for SK growth, which provide the theoretical basis to control the sizes and the shapes of QDs. Finally, we simulate the morphological evolution of SK system.