Berlin 2005 – wissenschaftliches Programm

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DS: Dünne Schichten

DS 20: Schichtwachstum

DS 20.3: Vortrag

Dienstag, 8. März 2005, 15:45–16:00, TU HS107

Growth kinetics of InGaAsN quantum wells analysed by transmission electron microscopy — •Martin Albrecht¹, Ines Häsuler¹, Thilo Remmle¹, Lutz Geelhaar², and Henning Riechert² — ¹Institut für Kristalzüchtung, Max-Born-Strasse 2, 12489 Berlin — ²Infineon Coporate Research Photonics, Otto-Hahn-Ring 6, 81730 München

Growth kinetics essentially influences the structural and thus optical properties of quantum wells based on InGaAsN. Although it is well known that InGaAsN undergoes a transition from 2D- to 3D growth with increasing growth temperature and increasing N-concentration a detailed study on the influence of N on the growth ofvthis pseudo ternary alloy is missing. In this contribution we present experimental work based on high resolution transmission electron microscopy. InGaAs, GaAsN and InGaAsN samples are grown by radio frequency plasma source molecular beam epitaxy in the temperature range between 400^∘C-450^∘C. We study the transition from 2D growth to 3D growth as dependent on temperature, layer thickness and growth rate. Our results clearly show that it is the interaction of In and N that causes 3D growth. Energy filtered transmission electron microscopy reveals that N-incorporation decreases with increasing In-content. In case of 3D-growth a reduced In-concentration is found in the wetting layer. We discuss our experimental findings in terms of In-segregation facilitated by N.