ISSN:
1089-7550
Source:
AIP Digital Archive
Topics:
Physics
Notes:
X-ray diffraction θ–2θ scans and kinematical simulations were used to study the composition modulation in coherently strained ten period InxGa1−xAs/GaAs superlattices grown by molecular beam epitaxy (MBE). Superlattice periods (Λ) were 34.5, 55.0, and 92.0 Å, each with nominally 10-Å-thick In0.5Ga0.5As layers. Simulations using exponential In composition modulations, as expected due to In segregation during MBE growth, produced the best fits to the experimental data. The measured 1/e segregation lengths ranged from 11 to 16 Å. Since this distance was larger than the InGaAs layer thickness, the maximum In concentration reached in the samples was only x(approximate)0.20–0.25. For the Λ=34.5 Å sample, since the GaAs layer was also thin, the composition modulation varied with each period of the superlattice. The simulation also showed layer thickness fluctuations which varied from 1.0 to 2.0 Å for the InGaAs layers and 2.0–3.0 Å for the GaAs layers. © 1998 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.366930
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