BRILLOUIN-SCATTERING FROM SURFACE PHONONS IN AL-COATED SEMICONDUCTORS

Brillouin spectra from thermally excited surface acoustic phonons in GaAs and Si surfaces coated with a thin Al film are presented. The measurements show features different from the Al and the semiconductor surfaces. We are able to give a theoretical explanation of the experimental results in terms of the coupling between the normal modes of the film and of the substrate. © 1979 The American Physical Society.