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HL: Fachverband Halbleiterphysik

HL 22: Heterostructures, Interfaces and Surfaces

HL 22.6: Vortrag

Mittwoch, 7. September 2022, 16:45–17:00, H33

Determination of relaxation in thin InGaAs-films by Raman spectroscopy — •Johann Friedemann Schulz¹, Tobias Henksmeier², Martin Feneberg¹, Elias Kluth¹, Dirk Reuter², and Rüdiger Goldhahn¹ — ¹Otto von Guericke University, Institute of Physics, Universitätsplatz 2, 39106 Magdeburg, Germany — ²Paderborn University, Department of Physics, Warburger Str. 100, 33089 Paderborn, Germany

Semiconductor heterostructures suffer inherently from differences in their lattice parameters. This causes strain and, in the worst case, crystal defects in the material, rendering it potentially unusable for electronic or optical devices. The relaxation of thin mismatched films is therefore important for assessing the crystal quality. One possibility to experimentally access the degree of relaxation is to accuractely determine the phonon frequencies of the strained material, as Phonon frequencies depend on composition and lattice parameters. Such measurements can be carried out quickly and easily using Raman spectroscopy. Here, we present results on InxGa1-xAs grown on GaAs-substrates by molecular beam epitaxy. We investigate different strained films with varied composition and several different film thicknesses. We find Raman spectroscopy a viable tool to determine the degree of relaxation even in films which are too thin for usual reciprocal space map experiments.