Ghorbel N, Kallel A, Damamme G
LaMaCoP, Faculty of Sciences of Sfax, University of Sfax, BP 3018, Sfax, Tunisia.
LaMaCoP, Faculty of Sciences of Sfax, University of Sfax, BP 3018, Sfax, Tunisia.
Micron. 2018 Sep;112:35-41. doi: 10.1016/j.micron.2018.06.002. Epub 2018 Jun 12.
The study of secondary electron emission (SEE) yield as a function of the kinetic energy of the incident primary electron beam and its evolution with charge accumulation inside insulators is a source of valuable information (even though an indirect one) on charge transport and trapping phenomena. We will show that this evolution is essentially due, in plane geometry conditions (achieved using a defocused electron beam), to the electric field effect (due to the accumulation of trapped charges in the bulk) in the escape zone of secondary electrons and not to modifications of trapping cross sections, which only have side effects. We propose an analytical model including the main basic phenomena underlying the space charge dynamics. It will be observed that such a model makes it possible to reproduce both qualitatively and quantitatively the measurement of SEE evolution as well as to provide helpful indications concerning charge transport (more precisely, the ratios between the mobility and diffusion coefficient with the thermal velocity of the charge carrier).
研究二次电子发射（SEE）产额与入射一次电子束动能的函数关系，以及其随绝缘体内部电荷积累的演变，是获取有关电荷传输和俘获现象的有价值信息的来源（尽管是间接信息）。我们将表明，在平面几何条件下（使用散焦电子束实现），这种演变主要是由于二次电子逃逸区内的电场效应（由于体内俘获电荷的积累），而不是俘获截面的变化，俘获截面变化只有副作用。我们提出了一个分析模型，其中包括空间电荷动力学的主要基本现象。可以观察到，这样一个模型能够定性和定量地再现SEE演变的测量结果，并提供有关电荷传输的有用指示（更准确地说，是迁移率与扩散系数之比与电荷载流子热速度的关系）。
