STUDY OF THE RAYLEIGH ACOUSTIC MODE IN A-SI-H A-SINX-H SUPERLATTICES/

The Brillouin light-scattering technique has been exploited for;studyi ng the Rayleigh acoustic mode in superlattice films consisting of alte rnate layers of a-Si:H and a-SiNx:H. The phase velocity of the Rayleig h mode has been measured on superlattices with different thicknesses o f the a-Si:H layer. The results obtained have been interpreted in term s of the effective medium model within the elastic continuum approxima tion; no anomalous behavior is observed, in contrast with previous ult rasonic measurements in superlattice with a minor nitrogen content.