High‐quality Hg_1–xCd_xTe (MCT) single crystals are essential for two‐dimensional infrared detector arrays. Crystal quality plays an important role on the performance of these devices. Here, the dislocations present at the interface of CdZnTe (CZT) substrates and liquid‐phase epitaxy grown MCT epilayers are investigated using X‐ray Bragg diffraction imaging (XBDI). The diffraction contributions coming from the threading dislocations (TDs) of the CZT substrate and the MCT epilayers are separated using weak‐beam conditions in projection topographs. The results clearly suggest that the lattice parameter of the growing MCT epilayer is, at the growth inception, very close to that of the CZT substrate and gradually departs from the substrate's lattice parameter as the growth advances. Moreover, the relative growth velocity of the MCT epilayer around the TDs is found to be faster by a factor of two to four compared with the matrix. In addition, a fast alternative method to the conventional characterization methods for probing crystals with low dislocation density such as atomic force microscopy and optical interferometry is introduced. A 1.5 mm × 1.5 mm area map of the epilayer defects with sub‐micrometre spatial resolution is generated, using section XBDI, by blocking the diffraction contribution of the substrate and scanning the sample spatially.

中文翻译：

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使用单色X射线布拉格衍射成像研究穿线位错对HgCdTe外延层生长的作用

高质量汞_{1– x}镉_xTe（MCT）单晶对于二维红外探测器阵列必不可少。晶体质量对这些器件的性能起着重要作用。在这里，使用X射线布拉格衍射成像（XBDI）研究了CdZnTe（CZT）衬底和液相外延生长的MCT外延层界面处的位错。来自CZT基板和MCT外延层的螺纹位错（TD）的衍射贡献在投影形貌图中使用弱光束条件进行了分离。结果清楚地表明，生长的MCT外延层的晶格参数在生长开始时非常接近CZT衬底的晶格参数，并随着生长的进行逐渐偏离衬底的晶格参数。此外，与矩阵相比，发现TD周围MCT外延层的相对生长速度快了2到4倍。此外，介绍了一种替代传统表征方法的快速替代方法，用于探测低位错密度的晶体，例如原子力显微镜和光学干涉仪。使用XBDI切片，通过阻挡基材的衍射作用并在空间上扫描样品，生成了具有亚微米级空间分辨率的外延层缺陷的1.5 mm×1.5 mm面积图。