BEEM spectroscopy at interfaces of Au, Ag, Cu, Mg and Ni films with n-GaP(110)

A systematic investigation with ballistic-electron emission microscopy (BEEM) of local Schottky-barrier heights for ≅ 100 Å thick films of Au, Ag, Cu, Mg and Ni evaporated onto cleaved n-GaP(110) surfaces is presented. It is shown that the onset of the BEEM current follows a 5 2 power law, thermally broadened by the tip Fermi function. Schottky-barrier heights are found to be 1.41 ± 0.02 eV (Au), 1.27 ± 0.02 eV (Ag), 1.21 ± 0.03 eV (Cu), 1.03 ± 0.02 eV (Mg) and 1.06 ± 0.06 eV (Ni). In addition, the influence of varying injection geometry and tip contamination on the BEEM spectra is discussed. © 1991.