Scanning Electron NanoDiffraction (SEND) is a powerful and versatile technique for lattice strain mapping in nano-devices and nano-materials. The measurement is based on Bragg diffraction from a local crystal volume. However, the resolution and precision of SEND are fundamentally limited by the uncertainty principle and scattering that govern electron diffraction. Here, we propose to measure lattice strain using a focused probe and circular Hough transform to locate the position of non-uniform diffraction disks. Methods for fitting a 2D lattice to the detected disks for strain calculation are described, including error analysis. We demonstrate our technique on a FinFET device for strain mapping at the spatial resolution of 1 nm and strain precision of ∼3×10-4. Using this and simulations, the experimental parameters involved in data acquisition and analysis are thoroughly investigated to construct an optimum strain mapping strategy using SEND.

中文翻译：

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使用圆形霍夫变换进行电子衍射盘检测的晶格应变映射

扫描电子纳米衍射 (SEND) 是一种强大且通用的技术，用于纳米器件和纳米材料中的晶格应变映射。测量基于来自局部晶体体积的布拉格衍射。然而，SEND 的分辨率和精度从根本上受到控制电子衍射的不确定原理和散射的限制。在这里，我们建议使用聚焦探针和圆形霍夫变换来测量晶格应变，以定位非均匀衍射盘的位置。描述了将 2D 晶格拟合到检测到的磁盘以进行应变计算的方法，包括误差分析。我们在 FinFET 器件上展示了我们的技术，用于以 1 nm 的空间分辨率和 ~3×10-4 的应变精度进行应变映射。使用这个和模拟，