Low-energy ion-induced Auger electron spectra of solid al and Si: Angle-resolved spectra and Monte Carlo simulations

Abstract The Auger spectra of solid Al and Si induced by low-energy ion impact in the LVV region show band structures, due to electron emission from the bulk, and narrow structured peaks due to the emission from sputtered excited atoms. The shape of the atomic peaks has been systematically investigated for ion energies of 3–6 keV, incident angles of 45° and 80° and various angles of detection. It was found to be strongly influenced by these parameters. Since the line shape is affected by the Doppler effect, the Monte Carlo simulation program TRIM.SP [1,2], which provides the velocity distribution of the sputtered atoms, was used for the interpretation of the experimental results. The program was modified to include the process of inner-shell excitations and subsequent Auger electron emission. It turned out that the pronounced structure of the atomic peaks can be explained in terms of the velocity distribution of the excited sputtered atoms, which is completely different from that of sputtered ground-state atoms.