Published online by Cambridge University Press: 28 February 2011
The strain in MBE GaAs/Si heterostructures grown with a buffer layer are characterized by Raman scattering and luminescence. A graded thickness sample was produced by slowly moving a shutter in front of the sample during the growth. Raman scattering and luminescence measurements made as a function of distance could be related to the strain in the film as a function of film thickness. The measurements showed tensile strain for all thicknesses. The strain in the overlayer was accounted for by the difference in thermal expansion of GaAs and Si. The buffer layer showed the largest tensile strain, and it is proposed that this strain was due to the presence of vacancies.