Cazaux Jacques
Laboratoire d'Ingénierie et Sciences des Matériaux (LISM), EA 4695, Faculty of Sciences, Reims Cedex 2, France.
J Electron Microsc (Tokyo). 2012;61(5):261-84. doi: 10.1093/jmicro/dfs048. Epub 2012 Aug 7.
Image formation in scanning electron microscopy (SEM) is a combination of physical processes, electron emissions from the sample, and of a technical process related to the detection of a fraction of these electrons. For the present survey of image contrasts in SEM, simplified considerations in the physics of the secondary electron emission yield, δ, are combined with the effects of a partial collection of the emitted secondary electrons. Although some consideration is initially given to the architecture of modern SEM, the main attention is devoted to the material contrasts with the respective roles of the sub-surface and surface compositions of the sample, as well as with the roles of the field effects in the vacuum gap. The recent trends of energy filtering in normal SEM and the reduction of the incident energy to a few electron volts in very low-energy electron microscopy are also considered. For an understanding by the SEM community, the mathematical expressions are explained with simple physical arguments.
扫描电子显微镜（SEM）中的图像形成是一个物理过程、样品电子发射以及与这些电子一部分检测相关的技术过程的组合。对于本次SEM图像对比度的综述，二次电子发射产额δ的物理学简化考量与发射的二次电子部分收集的效应相结合。尽管最初会对现代SEM的架构有所考虑，但主要关注点在于材料对比度，包括样品次表面和表面成分的各自作用，以及真空间隙中场效应的作用。还考虑了常规SEM中能量过滤的最新趋势以及极低能量电子显微镜中将入射能量降低到几电子伏特的情况。为了便于SEM领域的人员理解，用简单的物理论据对数学表达式进行了解释。
