Nowadays electron channeling contrast imaging (ECCI) is widely used to characterize crystalline defects on blanket semiconductors. Its further application in the semiconductor industry is however challenged by the emerging rise of nanoscale 3D heterostructures. In this study, an angular multi-segment detector is utilized in backscatter geometry to investigate the application of ECCI to the defect analysis of 3D semiconductor structures such as III/V nano-ridges. We show that a low beam energy of 5 keV is more favorable and that the dimension of 3D structures characterized by ECCI can be scaled down to ~ 28 nm. Furthermore, the impact of device edges on the collected ECCI image is investigated and correlated with tool parameters and cross-section profiles of the 3D structures. It is found that backscattered electrons (BSE) emitted from the device edge sidewalls and generating the bright edges (edge effects), share a similar angular distribution to those emitted from the surface. We show that the collection of low angle BSEs can suppressed the edge effects, however, at the cost of losing the defect contrast. A positive stage bias suppresses edge effects by removing the inelastically backscattered electrons from the sidewalls, but low loss BSEs from the sidewalls still contribute to the ECCI micrographs. On the other hand, if segments of an angular backscatter (ABS) detector are properly aligned with the nano-ridges, BSEs emitted from the sidewall and the surface can be separated, thus leading to the completely absence of one bright edge on the surface without compromise of the defect contrast. The merging of two such ECCI images reveals the nano-ridge surface without edge effects.

中文翻译：

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通过适当的探测器配置将电子通道对比成像应用于 3D 半导体结构

如今，电子通道对比成像 (ECCI) 广泛用于表征覆盖半导体上的晶体缺陷。然而，它在半导体行业的进一步应用受到纳米级 3D 异质结构新兴兴起的挑战。在这项研究中，在反向散射几何中使用角度多段检测器来研究 ECCI 在 III/V 纳米脊等 3D 半导体结构的缺陷分析中的应用。我们表明 5 keV 的低光束能量更有利，并且以 ECCI 为特征的 3D 结构的尺寸可以缩小到 ~ 28 nm。此外，研究了设备边缘对收集的 ECCI 图像的影响，并将其与工具参数和 3D 结构的横截面轮廓相关联。发现从器件边缘侧壁发射并产生明亮边缘（边缘效应）的背散射电子 (BSE) 与从表面发射的背散射电子具有相似的角分布。我们表明，低角度 BSE 的集合可以抑制边缘效应，但是，代价是失去缺陷对比度。正级偏置通过从侧壁去除非弹性背散射电子来抑制边缘效应，但侧壁的低损耗 BSE 仍然有助于 ECCI 显微照片。另一方面，如果角背散射 (ABS) 检测器的片段与纳米脊正确对齐，则从侧壁和表面发射的 BSE 可以分离，从而导致表面上完全没有一个明亮的边缘，而不缺陷对比度的妥协。