In this work, the charging effect and induced conductivity of SiO₂ thin films on Si substrate irradiated by penetrating electron beam (e-beam) are investigated based on numerical calculation and experiment. The numerical model is performed by considering the electron scattering, trapping, drift, diffusion and recombination, and solved by the Monte Carlo and finite difference method. The results show that, under e-beam irradiation, due to emission of secondary electrons (SEs) from the surface, the net charge density is positive near the surface, but negative inside the film. The net charge density and resulting negative charging intensity decrease under e-beam irradiation because of high electron mobility. With e-beam irradiation, the free electrons drift and diffuse to the meter and thus the sample current increases. Meanwhile, the transmission current remains unchanged due to the weak charging intensity. With the increasing beam energy, the transmission current increases to the beam current. The sample current and the induced current gain reach the maximum at the beam energy of 15 keV. The sample current and the induced conductivity at the steady state increase linearly with beam current. The induced current gain increases with the rising positive bias voltage. The influence of film parameters on the charge effect is also analyzed.

在这项工作中，SiO ₂的充电效应和感应电导率在数值计算和实验的基础上，研究了穿透电子束（电子束）辐照的硅衬底上的薄膜。通过考虑电子的散射，俘获，漂移，扩散和复合来建立数值模型，并通过蒙特卡洛和有限差分法求解。结果表明，在电子束照射下，由于二次电子（SEs）从表面发射，净电荷密度在表面附近为正，而在膜内部为负。由于高电子迁移率，电子束辐照下的净电荷密度和由此产生的负电荷强度降低。在电子束辐照下，自由电子漂移并扩散到仪表，因此样品电流增加。同时，由于弱充电强度，传输电流保持不变。随着束能量的增加，传输电流增加到束电流。光束电流为15 keV时，采样电流和感应电流增益达到最大值。稳态下的样品电流和感应电导率随电子束电流线性增加。感应电流增益随着正偏置电压的升高而增加。还分析了膜参数对电荷效应的影响。