X-ray focusing with efficient high-NA multilayer Laue lenses
X-ray focusing with efficient high-NA multilayer Laue lenses
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DOI：
10.1038/lsa.2017.162
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发表时间：
2018-03-23
影响因子：
19.4
通讯作者：
Hamm, Christian E.
中科院分区：
文献类型：
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作者：
Bajt, Sasa;Prasciolu, Mauro;Hamm, Christian E.
多层劳厄透镜是用于X射线有效聚焦的体衍射元件。通过我们引入的新制造技术，可以制造足够高数值孔径（NA）的透镜，以实现低于10 nm的焦斑尺寸。形成透镜的材料的交替层必须跨越纳米尺度上的宽范围的厚度，以实现实现高NA所需的X射线偏转角的必要范围。这对沉积工艺的精度和材料特性的控制都提出了挑战，材料特性通常随层厚度而变化。我们引入了一对新的材料-碳化钨和碳化硅-来制备具有光滑和尖锐界面的分层结构，并且没有阻碍先前透镜制造的材料相变。使用由该系统制造的一对多层劳厄透镜（MLL），我们在16.3 keV的光子能量下实现了8.4 x 6.8 nm（2）的二维聚焦，具有高衍射效率，并展示了分辨率远低于10 nm的样品扫描成像。高NA还允许投影全息成像在大范围的放大率上具有强相位对比。误差分析表明，实现1 nm聚焦的可能性。
Multilayer Laue lenses are volume diffraction elements for the efficient focusing of X-rays. With a new manufacturing technique that we introduced, it is possible to fabricate lenses of sufficiently high numerical aperture (NA) to achieve focal spot sizes below 10 nm. The alternating layers of the materials that form the lens must span a broad range of thicknesses on the nanometer scale to achieve the necessary range of X-ray deflection angles required to achieve a high NA. This poses a challenge to both the accuracy of the deposition process and the control of the materials properties, which often vary with layer thickness. We introduced a new pair of materials-tungsten carbide and silicon carbide-to prepare layered structures with smooth and sharp interfaces and with no material phase transitions that hampered the manufacture of previous lenses. Using a pair of multilayer Laue lenses (MLLs) fabricated from this system, we achieved a two-dimensional focus of 8.4 x 6.8 nm(2) at a photon energy of 16.3 keV with high diffraction efficiency and demonstrated scanning-based imaging of samples with a resolution well below 10 nm. The high NA also allowed projection holographic imaging with strong phase contrast over a large range of magnifications. An error analysis indicates the possibility of achieving 1 nm focusing.