论文标题
照明条件在P-N连接处的内置电场测量中的影响。
The influence of illumination conditions in the measurement of built-in electric field at p-n junctions by 4D-STEM
论文作者
论文摘要
动量解决的4D茎，也称为质量中心（COM）分析，已用于测量硅P-N结的远距离内置电场。研究了不同的茎模式的影响以及空间分辨率和电场灵敏度之间的权衡。比较了两种采集模式：纳米梁和低放大倍数（LM）模式。具有高速获取的无热噪声MEDIPIX3直接电子检测器已用于研究低电子束电流和毫秒停留时间对测得的电场和标准偏差的影响。结果表明，由于使用较大的探针大小，LM条件可能会低估电场值，但在信噪比上提供了几乎一个数量级的改进，导致检测极限为0.011mv/cm。据观察，COM结果不会随获取时间或电子剂量低至24 $ e^ - /a^2 $而变化，这表明电子束不影响内置的电场，并且该方法对于研究束敏感的材料可以强大，而在需要低剂量的情况下。
Momentum resolved 4D-STEM, also called center of mass (CoM) analysis, has been used to measure the long range built-in electric field of a silicon p-n junction. The effect of different STEM modes and the trade-off between spatial resolution and electric field sensitivity are studied. Two acquisition modes are compared: nanobeam and low magnification (LM) modes. A thermal noise free Medipix3 direct electron detector with high speed acquisition has been used to study the influence of low electron beam current and millisecond dwell times on the measured electric field and standard deviation. It is shown that LM conditions can underestimate the electric field values due to a bigger probe size used but provide an improvement of almost one order of magnitude on the signal-to-noise ratio, leading to a detection limit of 0.011MV/cm. It is observed that the CoM results do not vary with acquisition time or electron dose as low as 24 $e^-/A^2$, showing that the electron beam does not influence the built-in electric field and that this method can be robust for studying beam sensitive materials, where a low dose is needed.
