We rediscover the null ellipsometry principle for an outstanding image-contrast enhancement method for darkfield imaging. Simply by adding polarizers, compensators, and a photodiode sensor to a conventional darkfield imaging system and applying the null principle, Si nano-cylinder structures as small as D20 nm (H20 nm) on non-patterned wafer, and gap defects as small as 14.6 nm and bridge defects as small as 21.9 nm on 40 nm line and 40 nm space patterns (H40 nm), which are invisible in conventional darkfield imaging, can be distinguished from scattered noise. To the best of our knowledge, no method has been successful for identifying such small non-metal (silicon) nanoscale objects with such low magnification ($\times 20$) optics.

中文翻译：

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通过空椭偏仪对纳米物体进行超对比度增强的暗场成像

我们重新发现了零椭偏原理，这是一种用于暗场成像的出色图像对比度增强方法。只需在传统的暗场成像系统中添加起偏器，补偿器和光电二极管传感器，并应用零位原理，即可在无图案晶片上形成小至D20 nm（H20 nm）的Si纳米圆柱结构，并且将间隙缺陷减小至14.6在传统的暗场成像中不可见的40 nm线和40 nm空间图案（H40 nm）上的21.9 nm和桥缺陷小至21.9 nm，可以将它们与散射噪声区分开。据我们所知，没有一种方法能够成功地识别出具有如此低放大倍率的小型非金属（硅）纳米级物体（$\times 20$）光学。