一种基于聚焦离子束技术的环境透射电镜r光阑清理方法

摘要

光阑是透射电子显微镜电子光学系统的重要部件之一,其对透射电镜的成像质量有着重要的影响,然而原位环境透射电镜由于在使用中经常需要通入气氛并配合加热,因污染累积导致光阑的使用寿命大为降低.本文针对传统真空高温灼烧清理光阑方法需要较强的经验性及成功率低的缺点,提出一种新的光阑清理方法.该方法使用聚焦离子束(FIB)可定点、高效地清理光阑孔边缘的各种污染物,在恢复光阑孔圆度的同时又不会对光阑的其他部分造成损伤而引起失效.最终测试结果表明清理后的光阑满足透射电镜的使用要求,因此这种基于FIB技术的加工手段为电镜工作者提供了一种高效、精确和无损的光阑清理方法.%Aperture is one of the important parts of transmission electron microscopy ( TEM ) , which has a direct influence on the imaging quality. In the in situ environmental transmission electron microscopy ( ETEM) the objective aperture is often polluted. The traditional clean method is heating the aperture in vacuum to a temperature just below its vaporization temperature. However, the success rate of this method is low. In this paper, we report a focused ion beam ( FIB) based method to clean the aperture. FIB can mill all the kinds of pollutants around the holes with high precision without damaging other parts of the aperture. The final examination in TEM shows that the aperture cleaned with FIB can meet the requirements for normal use. This FIB based method has been proven to be efficient, precise and nondestructive for cleaning the heavily polluted aperture.