Effects of Carbon Contaminations on Electron-Induced Damage of SiO₂ Film Surface at Different Electron Primary Energies

Abstract

Dependence of the electron-induced damage of the clean and carbon-contaminated SiO 2 film surfaces during the Auger electron spectroscopy measurement was investigated under irradiation of electrons at different primary energies. The variation in the intensity of the Si-LVV elemental peak with the increase in the electron dose was measured and analyzed within the scheme of the two-step decomposition model [J. Surf. Sci. Soc. Jpn. 25, 212 (2004) (in Japanese)]. The results clearly revealed that the rate of the decomposition of SiO 2 induced by the electron irradiation is decreased by a small amount of carbon contaminations of ~0.03 nm thickness on the SiO 2 surface. The effects of carbon contaminations on the reduction in the electron-induced degradation of SiO 2 is significant for the low-primary energy of electrons of 3 keV, and no effects were confirmed at the primary energy of 15 keV. These findings suggest that the primary energy dependence is attributed to the fact that interactions between primary electrons and atoms in the near surface region is much significant when primary electrons with the lower primary energy are irradiated.

Approach to Quantitative Evaluation of Electron-Induced Degradation of SiO2 Film Surface with Different Amounts of Carbon Contaminations

“…From these figures, it is confirmed that the decomposition cross sections tend to be smaller for the SiO 2 film surface with a larger amount of carbon contaminations under the irradiation of primary electrons. Note that the order of magnitude of σ 1 and σ 2 is similar to those reported previously [9][10][11][12]15].…”

“…16, it is found that the dependence of the electron-induced damage on the initial amount of carbon contaminations is significant for the lower beam current. Although the role played by carbon contaminations in the reduction of the electron-induced damage of SiO 2 is not clear at present, the carbon contamination layer is considered to behave as the protective capped layer for the decomposition of SiO 2 [1,15]. The carbon contaminations are desorbed with the increase in the electron dose probably by the oxidation by oxygen decomposed from SiO 2 .…”

“…In the previous study, effects of carbon contaminations existing on the SiO 2 film surface on the electron-induced damage were investigated [15]. The build-up of the elemental Si-LVV peak due to the electron-induced damage was quantitatively analyzed within the scheme of the two-step decomposition model [9][10][11][12].…”

24 h stability of thick multilayer silicene in air

“…Figure 5 displays the AES spectrum acquired just after preparation of the film (top spectrum), then the spectra are recorded in the same measurement conditions after 7 min and next after 24 h of air exposure. One notices that upon air exposure most of the oxidation process of the silicene film (presence of SiO 2 signal, 82 eV [45][46][47], or Si suboxides [46,47]) has occurred within 7 min. However, even after 24 h in air, this 43 MLs silicene film remains largely intact, being oxidized only at its top Typically, the Si LVV signal reveals that the Si-Si bonds largely dominate over Si-O ones [46,47].…”