Structural calibration of tensile-strained GaAs/InAlAs quantum wells
A set of novel lattice-mismatched quantum-well structures is investigated. These samples are composed of tensile-strained GaAs double quantum wells contained within relaxed InxAl1-xAs layers which are lattice mismatched with the GaAs substrate. The in-situ calibration of the alloy composition and growth rate by reflection high-energy electron diffraction (RHEED) is compared with ex-situ characterization techniques which include double-crystal X-ray diffractometry and transmission electron microscopy (TEM). Further analysis of the sample structure is performed using Taupin-Tagaki equations based on dynamical scattering theory. Generally, the postgrowth characterization results suggest that RHEED oscillation calibration is still an effective tool for the material system used in this research to obtain information on growth rates and alloy composition. However, it is noticed that the In mole fraction determined by X-ray diffraction has a deviation from predicted values by RHEED oscillation. This deviation was ascribed to the strain effect on the incorporation of indium atoms.
Publication Source (Journal or Book title)
Microwave and Optical Technology Letters
Meng, Q., Daniels-Race, T., & Lowe, W. (2001). Structural calibration of tensile-strained GaAs/InAlAs quantum wells. Microwave and Optical Technology Letters, 28 (2), 143-147. https://doi.org/10.1002/1098-2760(20010120)28:2<143::AID-MOP20>3.0.CO;2-0