Hu Min-Hui, Le Guen Karine, André Jean-Michel, Jonnard Philippe, Meltchakov Evgueni, Delmotte Franck, Galtayries Anouk
Laboratoire Chimie Physique-Matière Rayonnement, UPMC Université Paris 06, CNRS UMR 7614, Paris, France.
Opt Express. 2010 Sep 13;18(19):20019-28. doi: 10.1364/OE.18.020019.
We present the results of an optical and chemical, depth and surface study of Al/Mo/SiC periodic multilayers, designed as high reflectivity coatings for the extreme ultra-violet (EUV) range. In comparison to the previously studied Al/SiC system, the introduction of Mo as a third material in the multilayer structure allows us to decrease In comparison to the previously studied Al/SiC system with a reflectance of 37% at near normal incidence around 17 nm, the introduction of Mo as a third material in the multilayer structure allows us to decrease the interfacial roughness and achieve an EUV reflectivity of 53.4%, measured with synchrotron radiation. This is the first report of a reflectivity higher than 50% around 17 nm. Time-of-flight secondary ion mass spectrometry (ToF-SIMS) and x-ray photoelectron spectroscopy (XPS) measurements are performed on the Al/Mo/SiC system in order to analyze the individual layers within the stack. ToF-SIMS and XPS results give evidence that the first SiC layer is partially oxidized, but the O atoms do not reach the first Mo and Al layers. We use these results to properly describe the multilayer stack and discuss the possible reasons for the difference between the measured and simulated EUV reflectivity values.
我们展示了对Al/Mo/SiC周期性多层膜进行光学、化学、深度和表面研究的结果，该多层膜被设计用作极紫外（EUV）波段的高反射率涂层。与之前研究的Al/SiC系统相比，在多层结构中引入Mo作为第三种材料，相较于之前研究的在17nm左右近正入射时反射率为37%的Al/SiC系统，能使我们降低界面粗糙度，并通过同步辐射测量实现53.4%的EUV反射率。这是关于在17nm左右反射率高于50%的首次报道。对Al/Mo/SiC系统进行了飞行时间二次离子质谱（ToF-SIMS）和X射线光电子能谱（XPS）测量，以分析堆叠结构中的各个层。ToF-SIMS和XPS结果表明，第一层SiC被部分氧化，但O原子未到达第一层Mo和Al层。我们利用这些结果正确描述多层堆叠结构，并讨论测量的和模拟的EUV反射率值之间差异的可能原因。
