场发射扫描电镜中荷电现象研究  

Investigation on charging for field emission scanning electron microscope

作　　者：华佳捷[1] 刘紫微[1] 林初城[1] 吴伟[1] 曾毅[1] 

机构地区：[1]中国科学院上海硅酸盐研究所,上海200050

出　　处：《电子显微学报》2014年第3期226-232,共7页Journal of Chinese Electron Microscopy Society

基　　金：上海市科学技术委员会科研计划纳米技术项目(No.11nm0506900);上海硅酸盐研究所科技创新重点项目(No.Y37ZC4141G)

摘　　要：荷电效应是导致扫描电子显微镜(SEM)图像产生缺陷最重要原因之一,它使图像出现异常反差、畸变等现象,严重影响图像质量。镀膜可以有效避免荷电现象,但镀膜不可避免地会一定程度上掩盖样品的真实显微结构。如何在不镀膜的情况下,最大程度减少荷电现象以获得不导电材料真实显微结构特征是材料科学工作者和电镜工作者的共同追求。本文从荷电效应产生的机理出发,阐述了采用合适的加速电压、探测器以及扫描方式等实验参数,对常见的不导电样品,如聚丙烯球、氧化镧粉体、SiO2球以及羟基磷灰石粉末等样品进行显微结构表征。结果表明若选择合适的实验参数,在不镀膜的情形下可以显著减少荷电甚至使荷电完全消失,从而得到高质量的材料真实显微结构信息。Charge effect is one of the most important factors resulting in image defects for SEM.It seriously influences the image quality,such as abnormal contrast,distortion etc.Coating is an usual way to prevent the charge phenomenon,but it is unavoidable to cover the true microstructure of sample.How to minimize the charge phenomenon and obtain non-conductive materials＇ real microstructure without coating is the common pursuit of material scientists and electron microscopy technicians.In this paper,based on the mechanism of charge effect,we investigated the morphologies of several common non-conductive samples such as polypropylene balls,lanthanum oxide powders,SiO2 powders and hydroxyapatite powders by appropriate technical means,such as acceleration voltage,detectors and scan mode.Charge effect will be significantly reduced and even disappears completely if suitable experimental parameters are used,which will result in high-quality material images with true microstructure information.

关 键 词：扫描电镜 荷电效应 低加速电压 背散射像 

分 类 号：TN16[电子电信—物理电子学] TG115.215.3[金属学及工艺—物理冶金]