Asymmetry of misfit-dislocation induced satellite peaks in semiconductor heterostructures
| Autor: | J. Leininger, C. D. Moore, G. D. U’Ren, Mark S. Goorsky, R. Sandhu |
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| Rok vydání: | 1999 |
| Předmět: |
Diffraction
education.field_of_study Materials science Acoustics and Ultrasonics Condensed matter physics business.industry media_common.quotation_subject Population Bragg's law Heterojunction Condensed Matter Physics Asymmetry Surfaces Coatings and Films Electronic Optical and Magnetic Materials Condensed Matter::Materials Science Tilt (optics) Optics Dislocation business education Burgers vector media_common |
| Zdroj: | Journal of Physics D: Applied Physics. 32:A8-A11 |
| ISSN: | 1361-6463 0022-3727 |
| DOI: | 10.1088/0022-3727/32/10a/302 |
| Popis: | We examined GaAs/In0.05Ga0.95As/GaAs structures to quantify the relationship between misfit dislocation densities and the intensity of satellite peaks adjacent to the epitaxial layer Bragg reflections. Triple-axis x-ray diffraction rocking curves, double-axis x-ray topography and plan-view transmission electron microscopy were employed to confirm other theoretical work, which suggested that the diffuse scatter satellite peaks can be related to the density of misfit dislocations. Symmetric (004) triple axis -scans along the [110] direction showed an asymmetry in the satellite heights on either side of the coherent peak which can be attributed to a difference in the population of the misfit dislocation Burgers vectors. A (0.298?0.072) ?m-1 tilt of the diffuse scattered contribution (which includes the lobes) accompanied the lobe height asymmetry. Measurements taken along the [10] direction showed a reduction of intensity and more symmetric lobes. These results confirm that the lobes originate from misfit dislocations, that the difference in the lobe intensity provides information about the Burgers vectors, and that the lobe periodicity originates from the layer thickness and not from the distance between the dislocations. These results also indicate that triple axis rocking curve measurements can provide an assessment of the distribution of misfit dislocation Burgers vectors in semiconductor heterostructures with low-dislocation densities. |
| Databáze: | OpenAIRE |
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