INELASTIC-COLLISIONS OF NE ATOMS AND IONS WITH A SI SURFACE AND EFFECTS OF INITIAL-STAGES OF OXIDATION

Results of angle-resolved ion fraction measurements and an electron sp ectroscopy study of low keV Ne and Ne+ collisions with a Si surface ar e presented. Similar charge fractions for neutral and ionic projectile s are obtained, indicating that ion production occurs as a result of c ollisions with surface atoms. Production of Ne* autoionising states i s observed and its efficiency as a function of collision energy is det ermined. The characteristics of autoionising peak line shapes suggest differences in angular distributions of the different Ne* states. The effect of oxygen adsorption is studied and it is shown that exposure to oxygen results in a strong decrease of autoionising state productio n. Differences with oxygen adsorption on Mg and Al targets are underli ned.