A. Krost, F. Heinrichsdorff, D. Bimberg, J. Bläsing*, A. Darhuber**, G. Bauer**

Institut für Festkörperphysik, TU Berlin, Germany
*Institut für Experimentelle Physik, Otto-von-Guericke-Universität Magdeburg, Germany
** Institut für Halbleiterphysik, Johannes Kepler Universität Linz, Austria

X-ray analysis of Self-Organized InAs/InGaAs Quantum Dot Structure

We report on an X-ray study of an InAs/InGaAs/GaAs multi quantum dot stack grown by metalorganic chemical vapor deposition using grazing incidence reflectometry, high-resolution X-ray diffraction, reciprocal space mapping and pole figure analysis. No direct signal from the quantum dots is found by the high-resolution techniques. All rocking curves on different symmetric and asymmetric Bragg reflections can be simulated within the framework of dynamical theory assuming a perfect tretragonally distorted InAs/InGaAs/GaAs multiquantum well system. A pole figure analysis in the vicinity of the (113) and (022) reflections, however, reveals a signal from the quantum dots. There is a considerable indium enrichment in the quantum dots as compared to the wetting layer indicating a strong In-diffusion during their formation. Moreover, a strongly anisotropic diffuse scattering distribution with respect to the [110] and [1-10] directions is found.

PACS Numbers: 61.10i; 78.55C; 81.10B

The full text of this paper in pdf-Format:

If you came directly to this page, click this symbol  to go to the homepage of CRT.