Results of the measurement of the surface charging potential for PMMA films of various thicknesses under the effect of irradiation by electron beams of various energies are presented. The...

In this paper, a number of drawbacks and contradictions of the existing models of charging dielectric targets under irradiation with defocused electron beams of moderate energies (0.2–20 keV) are briefly noted. In order to streamline and coordinate all experimental results and theoretical information concerning the phenomenon of charging under electron irradiation, it was necessary to reconsider some postulates of the standard model based on a simple dependence of the electron emission coefficient σ on irradiating electron energy E₀. It is shown that the decisive role in establishing the equilibrium state of charging dielectrics is played by not only establishing the equilibrium value σ = 1, but also by reaching a certain critical value of the field F_in in the near-surface area of the target. This field is due to the generation of the two-layer bipolar distribution of charges. It enhances the electron emission owing to increasing the depth at which secondary electrons emerge and also owing to the previously neglected contribution of primary thermalized electrons. As a result, there occurs a fundamental transformation of the dependence of the total electron emission coefficient σ_c for a charged dielectric on the energy of primary electrons as compared to the case of an uncharged dielectric. Consequently, the value of the equilibrium energy E_2C, at which σ = 1, is changed. It is established that times of reaching equilibrium states for electron emission δ(t) and for surface potentials V_s(t) may differ by orders of magnitude. Also, the charging kinetics is significantly affected by the process of radiation-induced formation of defects in the irradiated dielectric, which results in two charging time constants—fast and long-term ones.

This article studied the resistance of the negative electron resist based on hydrogen-silsesquioxane (HSQ) depending on the dose of exposure in the process of Reactive Ion Etching (RIE). These...

Comprehensive experimental results on the kinetic characteristics of LiNbO ₃ charging process are reported. Secondary electron emission (SEE) yield, surface potential, and the sum of leakage and displacement currents were experimentally obtained during electron beam irradiation in the energy range from 200 eV to 10 keV for both sides of the Z -cut. We found that at the initial stage of charging, the SEE current that were collected by a hemispherical electrode changes its sign. It was explained by the emergence of a large displacement current on the collector. The direction of this current is opposite to the directions of SEE and backscattered electron currents. If a large positive charge arises on the surface of ferroelectrics, the positive displacement current dominates the secondary emission current; this fact was confirmed experimentally. Also, a high value of the negative surface potential in the electron energy range 200–700 eV for − Z cut of lithium niobate was found, though in this energy region, positive charging is observed for nonpolar dielectrics. The influence of domain repolarization currents on the measured emitted electrons and displacement current signals is shown.