Anisotropic materials, like carbon nanotubes (CNTs), are the perfect substitutes to overcome the limitations of conventional metamaterials; however, the successful fabrication of CNT forest metamaterial structures is still very challenging. In this study, a new method utilizing a focused ion beam (FIB) with additional secondary etching is presented, which can obtain uniform and fine patterning of CNT forest nanostructures for metamaterials and ranging in sizes from hundreds of nanometers to several micrometers. The influence of the FIB processing parameters on the morphology of the catalyst surface and the growth of the CNT forest was investigated, including the removal of redeposited material, decreasing the average surface roughness (from 0.45 to 0.15 nm) and a decrease in the thickness of the Fe catalyst. The results showed that the combination of FIB patterning and secondary etching enabled the growth of highly aligned, high-density CNT forest metamaterials. The improvement in the quality of single-walled CNTs (SWNTs), defined by the very high G/D peak ratio intensity of 10.47, demonstrated successful fine patterning of CNT forest for the first time. With a FIB patterning depth of 10 nm and a secondary etching of 0.5 nm, a minimum size of 150 nm of CNT forest metamaterials was achieved. The development of the FIB secondary etching method enabled for the first time, the fabrication of SWNT forest metamaterials for the optical and infrared regime, for future applications, e.g., in superlenses, antennas, or thermal metamaterials.

各向异性材料，例如碳纳米管（CNTs），是克服常规超材料的局限性的完美替代品。然而，碳纳米管森林超材料结构的成功制造仍然非常具有挑战性。在这项研究中，利用与附加的辅助蚀刻的聚焦离子束（FIB）的新方法被提出，它可以得到均匀的CNT和纳米结构森林为超材料的精细图案化和大小不等的小号从几百纳米至几微米。在FIB处理在催化剂表面的形态和CNT森林的生长参数的影响进行了研究，includ ING去除再沉积的材料，降低了平均表面粗糙度（从0.45到0.15 nm），并减少了Fe催化剂的厚度。结果表明FIB图案和二次蚀刻的结合使高取向，高密度CNT森林超材料的生长成为可能。单壁碳纳米管（SWNT）的质量提高（由极高的G / D峰比强度10.47定义），首次证明了碳纳米管森林的成功精细图案化。FIB图案深度为10 nm，二次蚀刻为0.5 nm，CNT林超材料的最小尺寸为150 nm。FIB二次蚀刻方法的发展首次实现了用于光学和红外领域的SWNT森林超材料的制造，以用于未来的应用，例如超透镜，天线或热超材料。