AUGER EMISSION BY IMPACT OF ENERGETIC ATOMS ON SI MONOLAYER(S)

We studied the Auger electron emission induced by energetic (600 and 9 00 eV) atoms bombardment in oblique incidence on Si films from submono layer to 4 monolayers (ML) thickness. Atomic and bulk contributions to the Si Auger emission were separately determined, and show a differen t trend versus film thickness. We ascribe these differences to the int erplay between processes (different mechanisms of sputter ejection, an d the Auger decay) that occur over different timescales. Atomic emissi on originating in prompt, projectile-target collisions is maximum at l ow coverage. Bulk emission intensity increases with coverage, as the c ascade regime (target-target collisions) fully develops. Surface sensi tivity has been found to be significantly larger for particle-induced Auger electron emission than for the conventional electron-induced Aug er emission.