Abstract The interpretation of images generated by scanning electron microscopes (SEMs) requires quantifiable and well-understood contrast. Furthermore, recent interest in probing samples using low-energy electrons to extract surface information is pushing towards the quantification of relative contrast in secondary-electron (SE) images. The detection and analysis of low-energy SEs remains at the heart of the development of such instruments and techniques. However, state-of-the-art SE detectors in most SEMs, which are largely using in-lens configurations, are mainly designed to favour the collection of primary-induced SEs, and hence fail to provide electron energy information that could be related to the sample composition. Here, we report on the development of a novel SE detector which makes use of the Bessel box (BB) electron energy analyser. We demonstrate a very compact analyser design (˜a volume of 12 mm3) through simulations and by acquiring an electron spectrum from a sample of graphene on copper. A resolution of 0.3% has been numerically computed and experimentally verified for the BB analyser.

中文翻译：

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使用贝塞尔箱式电子能量分析仪分析和检测扫描电子显微镜中的低能电子

摘要 扫描电子显微镜 (SEM) 生成的图像的解释需要可量化且易于理解的对比度。此外，最近对使用低能电子探测样品以提取表面信息的兴趣正在推动二次电子 (SE) 图像中相对对比度的量化。低能量 SE 的检测和分析仍然是此类仪器和技术发展的核心。然而，大多数 SEM 中最先进的 SE 探测器主要使用透镜配置，主要设计用于收集初级诱导的 SE，因此无法提供可能与样品组成。在这里，我们报告了一种利用贝塞尔盒 (BB) 电子能量分析仪的新型 SE 检测器的开发。我们通过模拟和从铜上的石墨烯样品中获取电子光谱，展示了一种非常紧凑的分析仪设计（约 12 mm3 的体积）。BB 分析仪的分辨率为 0.3%，已通过数值计算和实验验证。