Influence of carbon on the electron stimulated desorption from titanium silicide surfaces

The influence of carbon on the electron stimulated desorption from titanium silicide thin film surfaces has been studied by means of electron-stimulated-desorption (ESD) and Auger electron spectroscopy. The superficial carbon was due to exposure to air. The main ions ejected were O+, H+, and minor amounts of OH+. Ion emission intensity versus incident electron energy showed threshold energies corresponding to the Ti 3p and Si 2p core levels, in agreement with the Knotek–Feibelman model. Intensity and shape of the H+ ion yield curves depended markedly on the amount of carbon contamination remaining after Ar+ ion cleaning. Ion yield measurements on the low carbon concentration surfaces showed both thresholds due to excitation of the Ti 3p and Si 2p core levels. On the contrary, for high surface carbon concentrations, ions are only ejected by excitation of the Ti 3p levels. The differences between the ESD yield for H+ and O+ after exposure to air have been studied.