Phonon shifts and strains in strain-layered (Ga_1-xIn _x)As

Abstract

We have measured the phonon frequencies (Raman technique) and the strains (x-ray rocking curve technique) of (Ga1-xInx)As films on GaAs (100) substrates. Films with various x values and various thicknesses were studied. The films range from perfect epitaxial to those that have relaxed by different amounts. The strain-induced frequency shift was calculated for each sample using the phonon deformation constants and measured strains. From the measurements and calculation, it is shown that the frequency shifts due to strain and the equivalent bulk frequencies for the phonon give internal agreement. This indicates that the Raman technique can be used for in situ monitoring of the growth process.