He Xiaolong, Li Tianlong, Zhang Jia, Wang Zhenlong
Key Laboratory of Micro-systems and Micro-structures Manufacturing, Ministry of Education, Harbin Institute of Technology, Harbin 150080, China.
School of Mechatronics Engineering, Harbin Institute of Technology, Harbin 150001, China.
Micromachines (Basel). 2019 Oct 28;10(11):726. doi: 10.3390/mi10110726.
Controlled fabrication of 45 nm width nanowire using simulated emission depletion (STED) direct laser writing with a rod-shape effective focus spot is presented. In conventional STED direct laser writing, normally a donut-shaped depletion focus is used, and the minimum linewidth is restricted to 55 nm. In this work, we push this limit to sub-50 nm dimension with a rod-shape effective focus spot, which is the combination of a Gaussian excitation focus and twin-oval depletion focus. Effects of photoinitiator type, excitation laser power, and depletion laser power on the width of the nanowire are explored, respectively. Single nanowire with 45 nm width is obtained, which is λ/18 of excitation wavelength and the minimum linewidth in pentaerythritol triacrylate (PETA) photoresist. Our result accelerates the progress of achievable linewidth reduction in STED direct laser writing.
本文介绍了使用具有棒状有效焦点光斑的模拟发射损耗（STED）直接激光写入技术，可控制备宽度为45纳米的纳米线。在传统的STED直接激光写入中，通常使用环形损耗焦点，最小线宽限制为55纳米。在这项工作中，我们通过棒状有效焦点光斑将这个极限推到了50纳米以下的尺寸，该光斑是高斯激发焦点和双椭圆形损耗焦点的组合。分别研究了光引发剂类型、激发激光功率和损耗激光功率对纳米线宽度的影响。获得了宽度为45纳米的单根纳米线，其为激发波长的λ/18，也是季戊四醇三丙烯酸酯（PETA）光刻胶中的最小线宽。我们的结果加速了STED直接激光写入中可实现的线宽减小的进展。
