Secondary electron emission yield on poled silica based thick films

Abstract

Studies on the distribution of the electric field produced by a thermal poling process in a layer of Ge-doped silica on silicon substrate, by using secondary electron emission yield (SEEY) measurements (δ) are presented. Comparing ${\delta }_0$ between poled and unpoled areas, the SEEY at the origin of electron injection, we pointed out an electric field 0.5 μm below the surface for our poling conditions and directed in the same direction as the external field applied during the poling process. Then, the dependence of δ on the injected dose of electrons allows us to deduce that the poling process disturbs the glass structure strongly enough for leading to a weak conductivity. It is then easy to display the poled areas. We have also pointed out an effect of the electric properties of the glass on the measurements obtained with the Electron Probe for MicroAnalysis.