Ion Neutralization Processes at Insulator Surfaces and Consequent Impurity Migration Effects in SiO2Films

We have developed a model for the interaction of ions with insulator surfaces. This model describes in detail the processes whereby ions of different ionization potentials are neutralized at the surface and predicts that ion bombardment can cause impurity-ion migration in such films, depending on ionization potential. Such migration is demonstrated to occur, in agreement with the model, by use of radiotracer techniques employing ${}_{}{}^{22}{}_{}{}^{}\mathrm{Na}$ deposited on Si${\mathrm{O}}_2$ films.