BACKSCATTERING OF LOW-ENERGY (0-8 EV) ELECTRONS BY A SILICON SURFACE

An experimental apparatus and method for investigating elastic and ine lastic backscattering (180 degrees) of low-energy (0-8 eV) monoenerget ic electrons by a solid surface are described and the first results ar e presented for the reflection of electrons by samples of pure single- crystalline silicon with a polished surface (Si), doped p-type single- crystalline silicon with a porous surface (Si-p) as well as H2O and H2 O2 passivated porous samples, Si-p + H2O and Si-p + H2O2. A structure due to the excitation of surface plasmons has been observed for the fi rst time in the loss spectra, Features corresponding to a resonance ex cited state of molecular nitrogen adsorbed on the surface of porous si licon have been observed in the constant residual energy spectra. (C) 1997 American Institute of Physics. [S1063-7842(97)01604-8].