Signal optimization for transmission Kikuchi diffraction (TKD) measurements in the scanning electron microscope is investigated by a comparison of different sample holder designs. An optimized design is presented, which uses a metal shield to efficiently trap the electron beam after transmission through the sample. For comparison, a second holder configuration allows a significant number of the transmitted electrons to scatter back from the surface of the sample holder onto the diffraction camera screen. It is shown that the secondary interaction with the sample holder leads to a significant increase in the background level, as well as to additional noise in the final Kikuchi diffraction signal. The clean TKD signal of the optimized holder design with reduced background scattering makes it possible to use small signal changes in the range of 2% of the camera full dynamic range. As is shown by an analysis of the power spectrum, the signal-to-noise ratio in the processed Kikuchi diffraction patterns is improved by an order of magnitude. As a result, the optimized design allows an increase in pattern signal to noise ratio which may lead to increase in measurement speed and indexing reliability.

通过比较不同的样品架设计，研究了扫描电子显微镜中透射菊池衍射 (TKD) 测量的信号优化。提出了一种优化设计，该设计使用金属屏蔽在传输通过样品后有效地捕获电子束。为了进行比较，第二个支架配置允许大量透射电子从样品支架的表面散射回衍射相机屏幕。结果表明，与样品架的二次相互作用导致背景水平的显着增加，以及最终菊池衍射信号中的额外噪声。优化的支架设计的干净 TKD 信号与减少的背景散射使得使用相机全动态范围 2% 范围内的小信号变化成为可能。正如功率谱分析所示，处理后的菊池衍射图的信噪比提高了一个数量级。结果，优化的设计允许增加模式信噪比，这可能导致测量速度和索引可靠性的增加。