The positive charging effect of dielectric films irradiated by a focused electron beam

The surface potential of insulating thin films negatively charged by a low-energy focused electron beam

“…The beam current I B is 16 pA and the beam energy E B 2 keV. Here, the second critical energy has been simulated to be 1.6 keV for SiO 2 in our work (Li and Zhang, 2010) which is close to some simulation and experimental results (Renoud et al, 2004;Fakhfakh et al, 2008), although other higher values were reported (e.g. Yong et al, 1998).…”

“…Because the hole mobility is much less than the electron mobility in insulators, we use h = 10 −3 e . Although the charge trapping process is complicated in insulators (Cornet et al, 2008), we can simplify it by ignoring the trap capture cross-section and the de-trapping effect to reduce the computation time of simulation (Renoud et al, 2002;Li and Zhang, 2010). That is to say that a charge will be trapped if the charge density is lower than the constant trap density N T in a position.…”

“…We have further improved the model by adding electron-hole recombination, charge trapping and the SE redistribution at a film surface and accordingly clarified the positive charging effect of SiO 2 thin films (Li and Zhang, 2010).…”

“…The aim of the present work, therefore, is to reveal surface potential characteristics in the equilibrium state of grounded insulating thin films of several 100 nm thickness negatively charged by a low-energy (<5 keV) focused e-beam with our newly developed model (Li and Zhang, 2010) for the self-consistent simulation of charging effects. In this paper, we first outline the numerical model and then present simulation results of space charge, surface potential profile, and influences of e-beam and film parameters on the surface potential at center.…”

Enhanced detection of nanostructures by scanning electron microscopy using insulating materials

“…The simplicity of the technique could make nearly any SEM a useful tool for rapidly measuring and detecting conducting 1D structures. While previous efforts have shown that charging effects can be useful for the detection and measurement of 1D and/or nanostructured materials (Brintlinger et al, 2002;Homma et al, 2004;Li and Zhang, 2009), all require complex procedures for sample growth and/or scanning conditions. This method should make it highly useful for quickly detecting and assaying specimens suspected of containing nanostructures, making it perfect for use with the development of new synthesis routes for creating 1D materials.…”