宽束离子束刻蚀快速加工金属纳米间隙结构  

Rapid fabrication of metallic nanogap structures by shower ion beam etching

作　　者：曾沛 舒志文 陈艺勤 段辉高 郑梦洁 ZENG Pei;SHU Zhiwen;CHEN Yiqin;DUAN Huigao;ZHENG Mengjie(Jihua Laboratory,Foshan 528000,China;National Engineering Research Centre for High Efficiency Grinding,College of Mechanical and Vehicle Engineering,Hunan University,Changsha 410082,China)

机构地区：[1]季华实验室,广东佛山528000 [2]湖南大学机械与运载工程学院国家高效磨削工程技术研究中心,湖南长沙410082

出　　处：《光学精密工程》2023年第1期109-118,共10页Optics and Precision Engineering

基　　金：国家自然科学基金资助项目(No.12104182);季华实验室青年创新基金资助项目(No.X201321XQ200)。

摘　　要：提出并演示了利用宽束离子束刻蚀方法一次性对多个杠铃形金属纳米结构进行“横向抽减”,形成极小纳米间隙,从而实现多个金属纳米间隙结构的快速加工。利用电子束曝光定义图形化抗蚀剂结构,通过传统的金属沉积和湿法剥离将抗蚀剂图案转移至杠铃形金属纳米结构,最后使用宽束离子束刻蚀进行修剪。实验表明,精确控制刻蚀时间可以使杠铃形结构的两个纳米天线间的间隙距离达到10 nm以下,通过结合基于HSQ负性抗蚀剂的图案化工艺,可在HSQ纳米模板上制得悬空金属纳米间隙结构。利用表面结构形貌表征获得刻蚀过程中纳米结构的形态演变规律,并通过系统的实验和模拟验证了悬空金属间隙结构用于表面增强拉曼散射的优势。该方案为多个极小金属纳米间隙结构的一次成型提供了新的思路,在大面积拉曼传感衬底的低成本高效制备方面具有可观的应用前景。The use of shower ion beam etching for the "lateral extraction" of multiple diabolo-shaped metallic nanopatterns was proposed, enabling the direct and rapid fabrication of multiple metallic nanogap structures. In a typical process, after the nanostructured resist patterns were defined by electron beam lithography, traditional metal deposition and wet lift-off were performed to transfer the resist pattern to a diaboloshaped metallic nanostructure. The metallic patterns were then immediately trimmed using shower ion beam etching. The gap distance between two isolated nano-antennas could be narrowed to less than 10 nm by precisely controlling the etching time. In addition, combined with the hydrogen silsesquioxane(HSQ)-based negative-resist patterning process, free-standing metallic nanogaps atop HSQ nano-templates were obtained. The morphological evolution of nanostructures during the etching process was characterized.Systematic experiments and numerical simulations were conducted to verify the advantages of suspended metallic nanogap structures for surface-enhanced Raman scattering. The proposed process provides a new means for the one-time formation of multiple ultra-small metallic nanogap structures. It has promising application prospects in the low-cost and high-efficiency preparation of large-area Raman sensing substrates.

关 键 词：离子束刻蚀 电子束曝光 金属纳米间隙 亚10 nm 拉曼检测 

分 类 号：TN305.7[电子电信—物理电子学]