Secondary ion emission from polycrystalline Al under Cs+ irradiation

Abstract Work function and secondary ion intensity variations apparent during the initial stages of sputtering with 1 keV Cs+ ions have been recorded from Al under Cs+ irradiation. These are compared with each other and ion-induced L23MM Auger emissions induced through Ar+ and Xe+ irradiation. As expected, the Al+ and Al− intensities scale with the substrate work function in a manner consistent with the electron tunneling model. Likewise, the Al2+ population scales with the Auger signal consistent with a surface excitation initiated process. Furthermore, only single 2p vacancies were noted indicating that Al2+ forms from the sputtered Al+ population and Al+ forms from the sputtered Al0 population. The work function dependence exhibited by Al+ reveals that this is a minor process, at least for these ions under these conditions.