Characterization of UHV prepared Sb overlayers on (110) surfaces of III-V semiconductors

Abstract

Sb layers, prepared under UHV conditions by thermal evaporation onto cleaved surfaces of GaAs and InP, were investigated by Raman scattering and ellipsometry. Around half a monolayer of Sb a new peak evolves in the Raman spectra. It is attributed to substrate-overlayer vibrations, because its frequency depends on the substrate material. The broad structure of amorphous Sb becomes visible in the Raman spectra from 3 ML on. From the coverage dependence of the Rayleigh intensity a three-dimensional growth mode is suggested beyond 1 ML. Between 10 and 20 ML crystallization of the overlayer is observed. It becomes polycrystalline (D3d) with all the three-fold c axes oriented normal to the substrate surface (texture). © 1987 Elsevier Science Publishers B.V. (North-Holland Physics Publishing Division).