  Hot electron transport of direct and scattered carriers across an epitaxial
NiSi_2/n-Si(111) interface, for different NiSi_2 thickness, is studied using
Ballistic Electron Emission Microscopy (BEEM). We find the BEEM transmission
for the scattered hot electrons in NiSi_2 to be significantly lower than that
for the direct hot electrons, for all thicknesses. Interestingly, the
attenuation length of the scattered hot electrons is found to be twice larger
than that of the direct hot electrons. The lower BEEM transmission for the
scattered hot electrons is due to inelastic scattering of the injected hot
holes while the larger attenuation length of the scattered hot electrons is a
consequence of the differences in the energy distribution of the injected and
scattered hot electrons and the increasing attenuation length, at lower
energies, of the direct hot electrons in NiSi_2.
