The future applications of hyperbolic metamaterials demand stacks of materials with alternative ultra-thin conductive/dielectric films with good homogeneity of the thickness and reduced roughness level. In this work, the technology of pulsed-DC magnetron sputtering of aluminum was optimized using the Taguchi method in order to fabricate Al films with improved roughness level. The performed structural characterization proved the smaller Al domains and better homogeneity of the surface. The optimized process was used to fabricate a multilayer structure of Al/HfO_x as the metamaterial media. The fabricated structures were optically characterized in the UV/VIS range. The presented findings demonstrated the tunability effect of the effective reflectance of the examined stacks. The presented results are promising for the future application of multilayer structures in novel photonic devices based on hyperbolic metamaterials.

中文翻译：

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双曲超材料的超薄脉冲直流磁控溅射铝膜的优化

双曲线超材料的未来应用要求使用具有良好的厚度均匀性和降低的粗糙度水平的替代超薄导电/电介质膜来堆叠材料。在这项工作中，使用Taguchi方法对铝的脉冲直流磁控溅射技术进行了优化，以制造具有改善的粗糙度水平的Al膜。进行的结构表征证明较小的Al域和更好的表面均匀性。优化的工艺用于制造Al / HfO _x的多层结构作为超材料媒体。所制造的结构在UV / VIS范围内进行了光学表征。提出的发现证明了所检查的堆叠的有效反射率的可调性效应。所提出的结果对于多层结构在基于双曲线超材料的新型光子器件中的未来应用很有希望。