高通量扫描电子束显微镜是成像速度数倍甚至数十倍于常规扫描电子显微镜，具备自动拍照能力的一种新兴电镜设备。适用于对大面积、大体积样品有全景观测需求和高速成像的应用领域。依托聚束科技（北京）有限公司，本工作发展了一种单电子束类型的高通量扫描电镜，在导师指导和合作者协作下，建立了该电镜的大面积跨尺度材料观测方法，并实际应用在对数种材料的显微观测中。 本工作中发展的单束高通量扫描电镜，最大成像速度达到100M像素/秒，驻留时间10纳秒/像素。能同时对二次电子和背散射电子信号高速成像。以电子光学结构为核心研究点，研制了一种具有复合式电磁透镜、透镜内半导体二极管探测器、摇摆物镜式偏转系统融合的场发射扫描电子束镜筒，适用于低落点能量（≤3keV）、大落点电流（≥1nA）、高速成像的应用场景，极限分辨率达到1.5nm@1keV。在整体电镜系统设计提出了各模组如何配合提高成像通量的设计方案。本工作中的单束高通量扫描电镜具有单幅有效扫描场大、分辨能力强，信号电子收集效率高，成像信息丰富等特点。对比国外高端的扫描电镜，能够实现五倍到十几倍的成像通量提升。 随后在单束高通量扫描电镜的基础上发展了跨尺度阵列式连续拍照的方法，能获得了宏观到纳米尺度的全景图。将其应用于生命科学组织切片观测、半导体芯片分析、页岩油气储量分析、金属材料跨尺度观测领域，与国外产品相比，达到同样成像质量的前提下，显示了高通量成像的优势。在金属材料镍基单晶高温合金观测中，与合作者共同将单束高通量电镜与人工智能特征识别技术相结合，建立了一套完整的跨尺度图像采集和识别方法。单束高通量扫描电镜自动化、高分辨率、高通量、连续性的跨尺度表征能力改变了传统扫描电镜的微区抽样分析的使用方式，其跨尺度的表征手段有望广泛应用于更多的材料研究领域。
High-throughput scanning electron microscope is a new type electron microscope with imaging speed several times or even tens of times faster than conventional scanning electron microscopes, and can automatically take images. It’s suitable for application fields that require panoramic observation and high-speed imaging of large scale and large volume samples. Base on the technology of Focus e-Beam Technology (Beijing) Co. Ltd, this work developed a single-beam high-throughput scanning electron microscope. With the guidance of the supervisor and collaboration with collaborators, a large cross-scale material observation method was established and applied in the microscopic observation of several materials. The single-beam high-throughput scanning electron microscope developed in this work has a maximum imaging speed of 100M pixels/second and a dwell time of 10 nanoseconds/pixel. It can simultaneously take images with high-speed level of secondary electrons and backscattered electrons. The developed field emission electron column is suitable for high-speed imaging at low landing energy (≤ 3keV) and high probe current (≥ 1nA), which includes a combined magnetic and electrostatic objective lens, two semiconductor diode in-lens detectors and a swinging axis deflection system, and the best resolution is 1.5nm@1keV. A system design was proposed about how to coordinate the important modules to improve imaging through-put. The microscope developed in this work has the characteristics of large field of view, high resolution, high signal electron collection efficiency, and information-rich images. Compared to advanced scanning electron microscopes abroad, it can achieve a five to ten times increase in imaging throughput. Finally, a cross-scale array continuous microscopic photography was developed based on the single-beam high-throughput scanning electron microscope, obtaining a panoramic view from macroscopic to nanoscale. Applied to the fields of biology tissue slice observation, semiconductor chip analysis, shale oil and gas reserves analysis, and metal material cross-scale observation, it demonstrates the advantages of high-throughput imaging while achieving the same imaging quality as abroad products. For the cross-scale observation of nickel-based single crystal superalloys, the author cooperated with collaborators to combine artificial intelligence feature recognition technology and the microscope, has established a complete set of cross-scale image acquisition and recognition methods. The automatic, high-resolution, high-throughput, and continuous cross-scale photographic capability of single beam high-throughput scanning electron microscope has changed the way of microanalysis in traditional scanning electron microscope. The imaging characterization of cross-scale is expected to be widely applied in more material research fields.
