We demonstrate the use of both pixelated differential phase contrast (DPC) scanning transmission electron microscopy (STEM) and off-axis electron holography (EH) for the measurement of electric fields and assess the advantages and limitations of each technique when applied to technologically relevant samples. Three different types of samples are examined, firstly a simple highly-doped Si junction. Then a SiGe superlattice is examined to evaluate the effects of the mean inner potential on the measured signal. Finally, an InGaN/GaN microwire light-emitting diode (LED) device is examined which has a polarization field, variations of mean inner potential and a wurtzite crystal lattice. We discuss aspects such as spatial resolution and sensitivity, and the concept of pseudo-field is defined. However, the most important point is the need to limit the influence of diffraction contrast to obtain accurate measurements. In this respect, the use of a plane electron wave for EH is clearly beneficial when compared to the use of a convergent beam for pixelated DPC STEM.

中文翻译：

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通过像素化 STEM 和离轴电子全息术（或会聚光束与平面波）测量半导体器件的电特性。

我们演示了如何使用像素化微分相衬 (DPC) 扫描透射电子显微镜 (STEM) 和离轴电子全息术 (EH) 来测量电场，并评估每种技术在应用于技术相关样品时的优点和局限性。研究了三种不同类型的样品，首先是一个简单的高掺杂硅结。然后检查 SiGe 超晶格，以评估平均内电势对测量信号的影响。最后，研究了具有极化场、平均内电势变化和纤锌矿晶格的 InGaN/GaN 微线发光二极管 (LED) 器件。我们讨论了空间分辨率和灵敏度等方面，并定义了伪场的概念。然而，最重要的一点是需要限制衍射对比度的影响以获得准确的测量。在这方面，与使用会聚光束进行像素化 DPC STEM 相比，使用平面电子波进行 EH 显然是有益的。