Continuous-Time Modeling and Analysis of Particle Beam Metrology
Continuous-Time Modeling and Analysis of Particle Beam Metrology
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DOI：
10.1109/jsait.2023.3283911
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发表时间：
2023-03
期刊：
影响因子：
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通讯作者：
A. Agarwal;Minxu Peng;V. Goyal
中科院分区：
文献类型：
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作者：
A. Agarwal;Minxu Peng;V. Goyal
粒子束显微镜 (PBM) 通过按像素捕获标量值来执行纳米级成像，这些标量值表示在驻留时间内积分的二次电子 (SE) 响应的噪声测量值。扩展到计量学，目标包括估计每个像素的 SE 产量并检测像素间 SE 产量的差异；障碍包括粒子源中的散粒噪声以及仪器对单个 SE 响应的了解和变化。最近推出的时间分辨测量范式有望减轻源散粒噪声，但其分析和开发在很大程度上仅限于理想化下的估计问题，其中直接且完美地计数SE突发。在这里，分析扩展到特征检测问题中的误差指数以及代表估计问题的实际仪器行为的降级测量。对于根据理想化 SE 计数进行估计，还提供了对现有估计器和高级估计器的见解。为了在现实的 PBM 成像场景中进行估计，引入了对理想化模型的扩展，讨论了模型参数提取的方法，并提出了时间分辨数据的重大改进。
Particle beam microscopy (PBM) performs nanoscale imaging by pixelwise capture of scalar values representing noisy measurements of the response from secondary electrons (SEs) integrated over a dwell time. Extended to metrology, goals include estimating SE yield at each pixel and detecting differences in SE yield across pixels; obstacles include shot noise in the particle source as well as lack of knowledge of and variability in the instrument response to single SEs. A recently introduced time-resolved measurement paradigm promises mitigation of source shot noise, but its analysis and development have been largely limited to estimation problems under an idealization in which SE bursts are directly and perfectly counted. Here, analyses are extended to error exponents in feature detection problems and to degraded measurements that are representative of actual instrument behavior for estimation problems. For estimation from idealized SE counts, insights on existing estimators and a superior estimator are also provided. For estimation in a realistic PBM imaging scenario, extensions to the idealized model are introduced, methods for model parameter extraction are discussed, and large improvements from time-resolved data are presented.