Methodology for quantitative evaluation of electron radiation damage and calculation of tolerable electron dose was developed to achieve damage-less scanning electron microscope (SEM) observation of beam-sensitive polymer film. The radiation damage is typically evaluated with visual impressions of SEM images; however, this method may be unreliable because observer’s subjectivity may affect the results. Evaluation with quantitative value is crucial to improve reliability. In this study, the radiation damage was evaluated by using normalized correlative coefficient (RNCC) between an initial frame and latter frames of the multiple SEM images that were taken consecutively. Tolerable dose was obtained by defining a threshold point of RNCC where rapid reduction of RNCC started. A SEM image with less damage and acceptable signal-to-noise ratio was obtained by integrating the images from the initial frame to the tolerable frame.

中文翻译：

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扫描电子显微镜下电子剂量控制对聚合物的无损观察

开发了定量评估电子辐射损伤和计算容许电子剂量的方法，以实现对束敏感聚合物薄膜的无损伤扫描电子显微镜 (SEM) 观察。辐射损伤通常通过 SEM 图像的视觉印象来评估；但是，这种方法可能不可靠，因为观察者的主观性可能会影响结果。具有定量价值的评估对于提高可靠性至关重要。在这项研究中，通过使用连续拍摄的多个 SEM 图像的初始帧和后帧之间的归一化相关系数 (RNCC) 来评估辐射损伤。通过定义开始快速减少 RNCC 的 RNCC 阈值点来获得可耐受剂量。