Secondary ion emission from polycrystalline Al under Csþ irradiation

Work function and secondary ion intensity variations apparent during the initial stages of sputtering with 1 keV Csþ ions have been recorded from Al under Csþ irradiation. These are compared with each other and ion-induced L23MM Auger emissions induced through Arþ and Xeþ irradiation. As expected, the Alþ and Al intensities scale with the substrate work function in a manner consistent with the electron tunneling model. Likewise, the Al2þ population scales with the Auger signal consistent with a surface excitation initiated process. Furthermore, only single 2p vacancies were noted indicating that Al2þ forms from the sputtered Alþ population and Alþ forms from the sputtered Al0 population. The work function dependence exhibited by Alþ reveals that this is a minor process, at least for these ions under these conditions. # 2004 Elsevier B.V. All rights reserved.