In enrichment in (In,Ga)As/GaAs quantum dots studied by high-resolution x-ray diffraction and pole figure analysis

• Published in: Applied physics letters Vol. 75; no. 19; pp. 2957 - 2959
• Main Authors: Krost, A., Bläsing, J., Heinrichsdorff, F., Bimberg, D.
• Format: Journal Article
• Language: English
• Published: 08-11-1999
• ISSN: 0003-6951; 1077-3118
• DOI: 10.1063/1.125200

We report on an x-ray study of a 15×(InAs/InGaAs/GaAs) multiquantum dot stack grown by metal organic chemical vapor deposition using high-resolution x-ray diffraction 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 tetragonally distorted InAs/InGaAs/GaAs multiquantum well system. The analysis of the diffuse scattering intensity in the vicinity of the (113) reflection in the symmetric scattering geometry, however, reveals a signal from the quantum dots. The quantum dots consist of nearly pure InAs, whereas the mean In concentration in the wetting layer is only 43% indicating a strong In diffusion during the Stranski–Krastanow formation process.