We report on the fabrication of molybdenum (Mo) nanopillar (NP) arrays with NP diameters down to 75 nm by means of deep-reactive ion etching at cryogenic temperatures. A variable-thickness Mo metal layer sputtered onto a Si₃N₄/Si substrate makes possible NPs with different lengths in a controllable manner. We demonstrate how our fabrication strategy leads to tunable cross-sections with different geometries, including hexagonal, cylindrical, square and triangular shapes, by using electron beam lithography on hydrogen silsesquioxane negative tone resist. To ensure well-defined facets and surfaces, we employ deep-reactive ion etching in a gas mixture of SF₆ and O₂ at cryogenic temperatures in an inductively coupled plasma reactive ion etching (ICP-RIE) system. These results represent an attractive route towards the realization of high-density Mo NP arrays for applications from nanoelectronics to quantum sensing and hydrogen evolution reaction catalysis.

我们报告了在低温下通过深反应离子蚀刻制造纳米柱直径低至 75 nm 的钼 (Mo) 纳米柱 (NP) 阵列。溅射到 Si ₃ N ₄ /Si 衬底上的可变厚度 Mo 金属层使具有不同长度的纳米颗粒以可控方式成为可能。我们展示了我们的制造策略如何通过在氢倍半硅氧烷负性抗蚀剂上使用电子束光刻技术，获得具有不同几何形状（包括六边形、圆柱形、方形和三角形）的可调截面。为确保清晰的刻面和表面，我们在 SF ₆和 O ₂的气体混合物中采用深反应离子蚀刻在电感耦合等离子体反应离子蚀刻 (ICP-RIE) 系统中的低温下。这些结果代表了实现从纳米电子学到量子传感和析氢反应催化应用的高密度 Mo NP 阵列的有吸引力的途径。