基于扫描电子显微镜的二次电子发射系数测量

Measurement Method of Secondary Electron Yield Based on Scanning Electron Microscope

二次电子发射特性对许多领域的真空器件有着重要的影响,准确测量二次电子发射系数至关重要。本文介绍了一种基于扫描电子显微镜的二次电子发射系数的测量方法。利用扫描电子显微镜电子束流的高稳定性和电子能量的宽范围可调的特性,引入法拉第杯样品台,通过改变电子束扫描速度,放大倍数及聚焦状态等电镜参数,对平滑Ag的二次电子发射系数进行测量。结果显示,平滑Ag的二次电子发射系数不受电镜参数影响,且与参考文献测量结果相符合。本测试方法对于研究材料宽电子能量范围的二次电子发射特性具有重要的参考意义。

econdary electron emission characteristics have a significant impact on vacuum devices in many fields, and accurate measurement of secondary electron yield(SEY) is critical. In this paper, we present a method for measuring SEY based on scanning electron microscopy. We take advantage of the high stability of the electron beam current and the wide range of tunable electron energy, and add a specimen stage with Faraday cup to measure the SEY of smooth Ag by changing the scanning speed, magnification and focus state. The result shows that the secondary electron yield of smooth Ag is not affected by the electron microscopy parameters and is in accordance with the measurement result of the reference. This method is an important reference for the study of the secondary electron emission characteristics of the material over a wide incident electron energy range.