Electron beam-adsorbate interactions on silicon surfaces

The interactions which occur between electron beams in the energy range 0.5–2.5 keV, with currents of 0.1–1.0 microA and various adsorbates (H₂, CO, CH₄ and C₂H₄) on silicon surfaces have been investigated. The accumulation of beam induced dissociation products on the surface has been monitored by Auger spectroscopy, and the extent of electron stimulated desorption of neutral molecules has been determined mass spectroscopically. Thermal desorption spectra for various gases have also been obtained in order to compare adsorption behaviour with and without the presence of an electron beam. It is concluded that serious experimental errors may occur when LEED and AES are used in adsorption studies, particularly where comparatively weak binding energies are involved.