Genova Vincent J, Agyeman-Budu David N, Woll Arthur R
Cornell NanoScale Science and Technology Facility, Cornell University, Ithaca, New York 14853.
Department of Materials Science and Engineering, Cornell University, Ithaca, New York 14853 and Cornell High Energy Synchrotron Source, Cornell University, Ithaca, New York 14853.
J Vac Sci Technol B Nanotechnol Microelectron. 2018 Jan;36(1):011205. doi: 10.1116/1.4991875. Epub 2018 Jan 4.
Although the mechanisms of deep reactive ion etching (DRIE) of silicon have been reported extensively, very little by comparison has been discussed concerning DRIE of germanium. By directly comparing silicon and germanium etching in a time multiplexed DRIE process, the authors extract significant differences in etch mechanisms from a design of experiment and discuss how these differences are relevant to the design and fabrication of silicon and germanium collimating channel array x-ray optics. The differences are illuminated by characteristics such as reactive ion etching (RIE)-lag, aspect ratio dependent etching, and sidewall passivation. Specifically, the authors demonstrate the more severe nature of RIE-lag in germanium, especially at aspect ratios exceeding 13:1. In addition, the differences in the profile evolution between silicon and germanium are shown to be a result of differences in sidewall passivation. There is also a correlation between the different sidewall passivation and the inherent lack of scalloping in the case of germanium DRIE.
尽管关于硅的深反应离子刻蚀（DRIE）机制已有大量报道，但相比之下，关于锗的DRIE的讨论却很少。通过在时分复用DRIE工艺中直接比较硅和锗的刻蚀情况，作者从实验设计中提取了刻蚀机制的显著差异，并讨论了这些差异如何与硅和锗准直通道阵列X射线光学器件的设计和制造相关。这些差异通过诸如反应离子刻蚀（RIE）滞后、深宽比依赖刻蚀和侧壁钝化等特性得以体现。具体而言，作者证明了锗中RIE滞后更为严重的特性，尤其是在深宽比超过13:1时。此外，硅和锗之间轮廓演变的差异被证明是侧壁钝化差异的结果。在锗的DRIE情况下，不同的侧壁钝化与固有缺乏刻蚀微结构之间也存在关联。
