关键词: 绝缘物-半导体, 低能电子束, 中和特性, 表面电位, 放电特性

Abstract: Research on elimination of negative charging effects caused by high-energy electron beam (EB) irradiation is of great significance for the fabrication, detection and imaging of microelectronic devices. The discharge characteristics and neutralizing mechanism of insulator-semiconductor sample based on low-energy energy electron beam are studied through numerical simulation and experimental measurement. A numerical model based on electron scattering, transport and trapping is established, and the space charge, space potential distribution and discharge characteristics are investigated. The relaxation characteristics of space charges under the low-energy EB irradiation and the influences of beam energy and beam current on neutralizing characteristics are analyzed. The results show that the negatively charged strength of sample decreases gradually after long-term placement, but it cannot be eliminated completely due to the trapping effect. Under low-energy EB irradiation lower than the second critical energy, the negative charges are neutralized quickly and the surface potential tends to zero with the accumulation of positive charges. The transient time of neutralization process is the shortest when the landing energy of EB approaches to that of maximizing the total electron yield. The larger the beam current is, the faster the transient process achieves the equilibrium.Key

Key words: insulator-semiconductor, low-energyelectronbeam, neutralizingcharacteristic, surfacepotential, dischargecharacteristic