Ejection and Ionization Efficiencies in Electron and Ion-Stimulated Desorption from Covalently Bound Surface Structures
In this study we have examined the effects of substrate and modifier structure on the ion and electron-induced ejection of ions from surface species which are covalently attached to a metal oxide. The primary goal was to compare the ejection of parent and fragment ions induced by ion-stimulated desorption (1 KeV Ar+) to those ejected by electron-stimulated desorption (1 KeV) to ascertain which excitation method yielded a more reliable or sensitive mode for analysis of such surface structures. In the process of examining the analytical aspects of ESD vs SIMS we have observed marked similarities in the secondary ion energy spectra and total dissociation cross-sections for the two techniques, yet the ionization efficiencies are drastically different. Some indirect insight into the role played by the electronic component of the collision cascade in SIMS of these and related systems is thus provided.
KeywordsIonization Efficiency Valence Band Edge Collision Cascade Total Dissociation Si02 Valence
Unable to display preview. Download preview PDF.