LISM; EA 4695 Faculty of Sciences, BP 1039, 51687 Reims Cedex 2, France.
Ultramicroscopy. 2013 Dec;135:43-9. doi: 10.1016/j.ultramic.2013.06.002. Epub 2013 Jun 17.
Due to the influence of refraction effects on the escape probability of the Back-Scattered Electrons (BSE), an expression of the fraction of these BSE is given as a function of the beam energy, E°, and emission angle (with respect to the normal) α. It has been shown that these effects are very sensitive to a local change of the work function in particular for low emerging angles. This sensitivity suggests a new type of contrast in Low Voltage Scanning Electron Microscopy (LVSEM for E°<2 keV): the work function contrast. Involving the change of φ with crystalline orientation, this possibility is supported by a new interpretation of a few published images. Some other correlated contrasts are also suggested. These are topographical contrasts or contrasts due to subsurface particles and cracks. Practical considerations of the detection system and its optimization are indicated.
由于背散射电子（BSE）逃逸概率的折射效应的影响，给出了这些 BSE 的分数与束能 E°和发射角（相对于法线）α 的函数表达式。已经表明，这些效应对于低出射角的局部功函数变化特别敏感。这种敏感性表明了低电压扫描电子显微镜（对于 E°<2 keV 的 LVSEM）中的一种新型对比度：功函数对比度。涉及到 φ 随结晶方向的变化，这种可能性得到了一些已发表图像的新解释的支持。还提出了其他一些相关的对比度。这些是形貌对比度或由于亚表面颗粒和裂缝引起的对比度。还指出了检测系统及其优化的实际考虑因素。
