McCaffrey J P, Baribeau J M
Institute for Microstructural Sciences, National Research Council of Canada, Ottawa, Ontario, Canada.
Microsc Res Tech. 1995 Dec 1;32(5):449-54. doi: 10.1002/jemt.1070320507.
A calibration sample for transmission electron microscopy (TEM) has been developed that performs the three major instrument calibrations for a transmission electron microscope: the image magnification calibration for measurements of images, the camera constant calibration for indexing diffraction patterns, and the image/diffraction pattern rotation calibration for relating crystal directions to features in the image. This offers an improvement over commercially available calibration standards, where up to five different samples are required to perform these three calibrations. The new calibration sample consists of an electron-transparent cross-sectional TEM sample made from a molecular beam epitaxy (MBE)-grown, single-crystal semiconductor wafer. When the calibration structure is viewed in a TEM, it appears as a series of light and dark layers where the layer thicknesses are very accurately known. The calibrated thickness measurements of these light (silicon) and dark (SiGe alloy) layers are based on careful TEM measurements of the [111] lattice spacing of silicon which is visible on the calibration sample itself, and are supported by X-ray diffraction measurements. Furthermore, the layer thickness variation across the entire silicon wafer has been verified to be less than 1%, allowing all samples prepared from the same wafer to have errors in the given layer thickness values of less than 1%. As the sample is a single crystal of silicon, the calibrations requiring electron diffraction information such as the camera constant calibration and the image/diffraction pattern rotation calibration can also be performed easily and unambiguously. One single calibration sample can therefore be used to provide all three of the major TEM instrument calibrations at all magnifications and all camera lengths.
已开发出一种用于透射电子显微镜（TEM）的校准样品，它可对透射电子显微镜进行三项主要仪器校准：用于图像测量的图像放大率校准、用于衍射图谱索引的相机常数校准，以及用于将晶体方向与图像特征相关联的图像/衍射图谱旋转校准。这比市售校准标准有所改进，后者需要多达五个不同的样品才能进行这三项校准。新的校准样品由一个电子透明的横截面TEM样品组成，该样品由分子束外延（MBE）生长的单晶半导体晶片制成。在校透射电子显微镜观察校准结构时，它呈现为一系列明暗相间的层，其层厚度是非常准确已知的。这些亮层（硅）和暗层（硅锗合金）的校准厚度测量基于在校准样品本身上可见的硅的[111]晶格间距的仔细透射电子显微镜测量，并得到X射线衍射测量的支持。此外，已验证整个硅晶片上的层厚度变化小于1%，使得从同一晶片制备的所有样品在给定层厚度值上的误差小于1%。由于样品是硅单晶，因此需要电子衍射信息的校准，如相机常数校准和图像/衍射图谱旋转校准，也可以轻松且明确地进行。因此，一个校准样品可用于在所有放大倍数和所有相机长度下提供所有三项主要的透射电子显微镜仪器校准。
