Characteristics of secondary electron emission from few layer graphene on silicon (111) surface

Abstract

As a typical 2D coating material, graphene has been utilized to effectively reduce secondary electron emission from the surface. Nevertheless, the microscopic mechanism and the dominant factor of secondary electron emission suppression remain controversial. Since traditional models rely on experimental bulk properties data which is scarcely appropriate for the 2D coating situation, this paper presents a first-principles based numerical calculation of the electron interaction and emission process for monolayer and multilayer graphene on the silicon (111) substrate. By using the anisotropic energy loss for the coating graphene, the electron transport process can be described more realistically. The real physical electron interactions, including the elastic scattering of electron-nucleus, inelastic scattering of the electron-extranuclear electron and electron-phonon effect, are considered and calculated based on the Monte Carlo method. To be independent of experimental data, the energy level transition theory based first-principles method and the full Penn Algorithm are used to calculate the energy loss function during the inelastic scattering. Variations of the energy loss function and interface electron density difference for 1L to 4L layer graphene coating GoSi are calculated, and their inner electron distributions and secondary electron emission are analyzed. Simulation results demonstrate that the dominant factor of the SEY inhibition for GoSi is the mechanism by inducing electrons deeper during the internal scattering process. In contrast, a low surface potential barrier due to the positive deviation of electron density difference in monolayer GoSi interface inversely weakens the suppression of graphene layer on secondary electron emission. Only when the graphene layer number is 3L, the contribution of surface work function to the secondary electron emission suppression presents to be slightly positive.

Physical mechanism of secondary-electron emission in Si wafers

“…For a quantitative description of the SEY, the Monte Carlo method combined with scattering cross-section calculations would be the primary option. [45] However, because of the low doping concentration of our samples in the range between 0.781% and 3.125%, the doping systems (B(N)-doped Si wafers) constructed for the Monte Carlo simulations would be too large to properly account for the electron scattering by the impurities, which is computationally costly. Therefore, we theoretically studied the physical mechanism of N substitution in Si using first-principles calculations, and then experimentally investigated its effect on the structural and electrical properties.…”

Gas Desorption and Secondary Electron Emission from Graphene Coated Copper Due to E-Beam Stimulation

“…Graphene is widely used in electronic devices due to its excellent electrical properties, extremely high surface conductivity, and high thermal conductivity [34,35]. In our previous study, we also found that graphene has a good performance in suppressing secondary electrons [36,37]. However, in addition to the contribution of secondary electron emission, the microwave resonance-induced discharge is also closely related to the ionization excitation of electrons-gas collision [38].…”