We report on a new characterization method of 3D—doping performed by arsenic implantation into FinFET—like nanostructures by using Medium Energy Ion Scattering. Because of its good depth resolution (0.25 nm) at the surface, it is one of techniques of choice suitable to analyse the ultra-shallow doping of thin crystal films. However, with the constraints related to the nanostructures’ geometry and the low lateral resolution of the MEIS beam (0.5נ1 mm²), we developed an adequate protocol allowing their analysis with this technique. It encompasses three different geometries to account for the MEIS spectra of the arsenic implanted in each part of the nanostructures. The originality of the protocol is that, according to the chosen analysis geometry, the overall spectrum of arsenic is not the same because the contributions of each part of the patterns to its formation are different. By using two of them, we observed double peaks of arsenic. Thanks to 3D deconvolutions performed with PowerMEIS simulations, we were able to identify the contribution of the tops, sidewalls and bottoms in their formation. Thus, by separating the spectrum of the dopants implanted in the Fins (tops + sidewalls) from that of the bottoms, we were able to characterize the 3D doping conformity in the patterns. Two different implantation methods with the associated local doses computed in each single part were investigated. We found that the distribution of the dopants implanted by using the conventional implanter method is very different from that of plasma doping.

我们报告了一种新的3D表征方法，即通过使用中等能量离子散射，通过将砷注入FinFET进行的掺杂（如纳米结构）来进行掺杂。由于其在表面的良好深度分辨率（0.25 nm），它是适合分析薄膜的超浅掺杂的一种选择技术。但是，由于与纳米结构的几何形状和MEIS光束的横向分辨率低（0.5נ1 mm ²），我们开发了一种适当的协议，允许他们使用此技术进行分析。它包含三种不同的几何形状，以解释纳米结构各部分中注入的砷的MEIS光谱。该协议的独创性在于，根据所选的分析几何形状，砷的总光谱并不相同，因为图案各部分对其形成的贡献不同。通过使用其中两个，我们观察到了砷的双峰。借助PowerMEIS仿真执行的3D反卷积，我们能够确定顶部，侧壁和底部在其形成过程中的作用。因此，通过将鳍片（顶部+侧壁）中注入的掺杂剂的光谱与底部的光谱分开，我们能够表征图案中的3D掺杂一致性。研究了两种不同的植入方法，并在每个单个部分中计算了相关的局部剂量。我们发现，使用常规注入器方法注入的掺杂剂的分布与等离子体掺杂的分布有很大不同。