Dresden 2017 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 63: Poster: Quantum Dots and Optics

HL 63.79: Poster

Wednesday, March 22, 2017, 15:00–19:00, P1A

Investigation of spatial variation in molecular beam flux - gradients — •Vivienne Bippus, Rüdiger Schott, Pia Eickelmann, Julian Ritzmann, Andreas D. Wieck, and Arne Ludwig — Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, Universitätsstrasse 150, D-44780 Bochum, Germany

Semiconductor quantum wells (QWs) are essential tools for many research fields and devices such as LEDs, laser diodes or tunnel structures. To precisely control the emission wavelength, QWs are typically grown by molecular beam epitaxy (MBE) which offers monolayer precision. Due to the cell geometry of the MBE-setup, flux gradients can lead to spatial variations in the layer thickness on the wafer. A typical mitigation measure is to rotate the wafer during the epitaxy.

However, alloy composition and thickness variations of the QWs still appear. Therefore, we perform a systematic investigation to study the inhomogenities of the Ga, In and Al content via photoluminescence mapping of full three inch wafers. This will also be compared to MBE-growth without rotation, i.e. intentional flux gradients.