Voronov D L, Anderson E H, Cambie R, Cabrini S, Dhuey S D, Goray L I, Gullikson E M, Salmassi F, Warwick T, Yashchuk V V, Padmore H A
Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
Opt Express. 2011 Mar 28;19(7):6320-5. doi: 10.1364/OE.19.006320.
Ultra-high spectral resolution in the EUV and soft x-ray energy ranges requires the use of very high line density gratings with optimal design resulting in use of a Blazed Multilayer Grating (BMG) structure. Here we demonstrate the production of near-atomically perfect Si blazed substrates with an ultra-high groove density (10,000 l/mm) together with the measured and theoretical performance of an Al/Zr multilayer coating on the grating. A 1st order absolute efficiency of 13% and 24.6% was achieved at incidence angles of 11° and 36° respectively. Cross-sectional TEM shows the effect of smoothing caused by the surface mobility of deposited atoms and we correlate this effect with a reduction in peak diffraction efficiency. This work shows the high performance that can be achieved with BMGs based on small-period anisotropic etched Si substrates, but also the constraints imposed by the surface mobility of deposited species.
在极紫外（EUV）和软X射线能量范围内实现超高光谱分辨率需要使用具有优化设计的非常高线密度光栅，从而采用闪耀多层光栅（BMG）结构。在此，我们展示了具有超高刻槽密度（10,000线/毫米）的近乎原子级完美的硅闪耀基板的制造，以及该光栅上Al/Zr多层涂层的测量性能和理论性能。在入射角分别为11°和36°时，一阶绝对效率分别达到了13%和24.6%。横截面透射电子显微镜显示了沉积原子的表面迁移率所导致的平滑效果，并且我们将这种效果与峰值衍射效率的降低相关联。这项工作展示了基于小周期各向异性蚀刻硅基板的BMG所能实现的高性能，但同时也展示了沉积物种表面迁移率所带来的限制。
