Collective surface excitations in 3C-SiC(100)

Collective surface excitations at n-type 3C-SiC(100) surfaces, namely Fuchs-Kliewer phonons and plasmons, for different doping levels and surface reconstructions are studied by high resolution electron energy loss spectroscopy (HREELS). Auger electron spectroscopy (AES) and low energy electron diffraction (LEED) are used to monitor stoichiometry and surface reconstruction, The dipole scattering model using self-consistent electron density profiles is employed to calculate the dielectric response function and hence the expected loss spectrum. We find that this modelling reproduces general trends over a wide range of primary beam energies quite well and allows us to extract bulk electron densities, electron mobilities and the band bendings of different samples. However, for primary beam energies below approximately 7 eV a significant discrepancy between experimental and calculated energy loss spectra is revealed. Further studies are necessary to clarify this issue.