Raman Scattering Characterization of Strain in GaAs Heteroepitaxial Films Grown on Sapphire and Silicon-on-Sapphire Substrates

Publisher Website
Google Scholar
Abstract
We report results pertaining to the measurement of strain by Raman spectroscopy in GaAs epitaxial films grown by molecular beam epitaxy on sapphire and silicon-on-sapphire substrates. Comparative studies indicate that the GaAs layers deposited directly on sapphire substrates show no measurable strain, and only a small residual tensile strain is observed in the films grown on silicon-on-sapphire substrates. The magnitude of the strain in the GaAs/silicon-on-sapphire heterostructures is reduced by over a factor of 4.5 as compared to that observed in the GaAs films deposited directly on single-crystal silicon (100) substrates under the same growth conditions.