Dresden 2009 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 49: Quantum dots: preparation and characterization

HL 49.2: Vortrag

Freitag, 27. März 2009, 10:30–10:45, BEY 81

Growth of InAs Quantum Dots on Silicon substrates: Formation and Characterization — •Tariq Al-Zoubi, Emil-Mihai Pavelescu, and Johann Peter Reithmaier — Universität Kassel, Technische Physik, Institute of Nanotechnologies and Analytics (INA)

Self-assembled InAs quantum dots (QDs) were grown by solid source molecular beam epitaxy on different Si substrate orientations (100) and (111) using Stranski-Krastanov growth mode. The grown QDs were characterized using atomic force microscopy .The evolution of size and shape of quantum dots with InAs coverage was examined after ex-situ surface preparation (oxide desorption) of the Si wafers with (NH4)HF etchant and in-situ with temperature between 730°C-750°C (pyrometer). Dashed-like InAs dots of high density (9*10 to the 10th cm-2) were observed on (111) orientation compared to circular shaped QDs with a lower density (3.8*10 to the 10th cm-2) on (100) Si orientation. The dot size and density grew with increasing InAs coverage and growth temperature up to 425°C. A narrow dots size distribution was observed for 1.7 ML InAs coverage at a growth temperature of 400°C.