INTERFACE STRUCTURE OF GAAS/ALAS SUPERLATTICES GROWN ON (113) SURFACES - RAMAN-SCATTERING STUDIES

We present an analysis of the influence of the type of interface upon the Raman response of (113) oriented GaAs/AlAs superlattices. The atomic displacements are calculated using the bond charge model. Theoretical Raman spectra are obtained using the bond polarizability model. Spectra taken in the z(xy)($) over bar z configuration, with z parallel to [113], x parallel to [$($) over bar$$ 110] and y parallel to [$$($) over bar 332] are very sensitive to the presence of additional inplane periodicities. We have compared the theoretical Raman response with the experimental Raman spectra from samples grown by Molecular Beam Epitaxy. Although growth conditions favoured corrugated interfaces in these samples no characteristic feature of a perfectly corrugated interface in the experimental spectra is observed. Instead spectra are fitted better taken cationic mixing at the interface into account.