Experimental and Monte-Carlo study of double-hump electron emission yield curves of SiO2 thin films

In this work, we have made experimental measurements of multiple-hump total electron emission yield (TEEY) curves on SiO2 thin films. A Monte-Carlo electron transport model, published in Gibaru et al., J. Electron Spectrosc. Relat. Phenom. 261, 147265 (2022), has been developed to analyze the physical reasons of such atypical behavior. It is shown that the multiple-hump TEEY curves of thin dielectric layers are due to internal recombination effects. However, such kind of phenomenon is demonstrated to be strongly correlated to the incident current density. This analysis reveals that the double-hump TEEY curves observed commonly on insulators are also most probably a measurement artifact, tied to the operating parameters of the electron gun. A careful choice of experimental parameters can eliminate this artifact, by using a constant current density that is also low enough to limit recombination effects.

Automated summary

In this study, multiple-hump total electron emission yield (TEEY) curves on SiO2 thin films were experimentally measured. A Monte-Carlo electron transport model, published in Gibaru et al., J. Electron Spectrosc. Relat. Phenom. 261, 147265 (2022), has been developed to analyze the physical reasons behind this atypical behavior. It has been revealed that the multiple-hump TEEY curves of thin dielectric layers are caused by internal recombination effects. However, this phenomenon is strongly correlated to the incident current density. The analysis also suggests that the commonly observed double-hump TEEY curves on insulators are most likely a measurement artifact tied to the operating parameters of the electron gun. By carefully selecting experimental parameters, this artifact can be eliminated by using a constant current density that is also low enough to limit recombination effects.