ACS Appl Mater Interfaces. 2019 Oct 2;11(39):36177-36185. doi: 10.1021/acsami.9b09730. Epub 2019 Sep 23.
Recently, researchers have dedicated efforts toward producing large-area nanostructures using advanced lithography techniques and state-of-the-art etching methods. However, these processes involve challenges such as the diffraction limit and an unintended etching profile. In this work, we demonstrate large-area nanopatterning on a silicon substrate using the microscale metal mask by meticulous optimization of the etching process. Around the vertex of a microscale metal mask, a locally induced electric field is generated by a bias voltage applied on a silicon mold. We utilize this field to change the trajectory of reactive ions and their effect flux, thus providing a controllable bowing effect. The results are analyzed by both numerical simulations and experiments. Based on the field alignment by the metal mask for the etching (FAME) process, we demonstrate the fabrication of 378 nm-size nanostructure patterns which translate to a size reduction of 63% from 1 μm-size mask patterns on a wafer by optimization of the processes. This is much higher than the undercut (∼37%) usually achieved by a typical non-Bosch process under similar etching conditions. The optimized nanostructure is used as a mold for the transfer printing of nanostructure arrays on a flexible substrate to demonstrate that it enables the functionality of FAME-processed nanostructures.
最近，研究人员致力于使用先进的光刻技术和最先进的刻蚀方法来生产大面积的纳米结构。然而，这些过程涉及到如衍射极限和非预期的刻蚀轮廓等挑战。在这项工作中，我们通过对刻蚀过程的细致优化，使用微尺度金属掩模在硅衬底上进行大面积纳米图案化。在微尺度金属掩模的顶点周围，通过在硅模具上施加偏置电压产生局部诱导电场。我们利用这个场来改变反应离子的轨迹及其影响通量，从而提供可控的弯曲效应。结果通过数值模拟和实验进行了分析。基于金属掩模对刻蚀的场对准（FAME）过程，我们展示了在晶圆上从 1 微米尺寸掩模图案缩小 63%的 378nm 尺寸纳米结构图案的制造，这比在相似刻蚀条件下典型的非 Bosch 工艺通常实现的下切（约 37%）要高得多。优化后的纳米结构被用作在柔性衬底上转移打印纳米结构阵列的模具，以证明它能够实现 FAME 处理的纳米结构的功能。
