基于飞秒激光直写技术的金属图案化研究(特邀)  

Metal Patterning Based on Femtosecond Laser Direct Writing(Invited)

作　　者：庞茂璋 邱毅伟 曹春 匡翠方[3] Pang Maozhang;Qiu Yiwei;Cao Chun;Kuang Cuifang(School of Mechanical Engineering,Hangzhou Dianzi University,Hangzhou 310018,Zhejiang,China;Research Center for Intelligent Chips and Devices,Zhejiang Lab,Hangzhou 311121,Zhejiang,China;College of Optical Science and Engineering,Zhejiang University,Hangzhou 310027,Zhejiang,China)

机构地区：[1]杭州电子科技大学机械工程学院,浙江杭州310018 [2]之江实验室智能芯片与器件研究中心,浙江杭州311121 [3]浙江大学光电科学与工程学院,浙江杭州310027

出　　处：《中国激光》2024年第12期431-439,共9页Chinese Journal of Lasers

基　　金：国家自然科学基金(22105180);浙江省尖兵领雁重点研发项目(2023C01186、2023C01051);之江实验室重大科学项目(2020MC0AE01);浙江省自然科学基金(LQ22F050017)。

摘　　要：飞秒激光直写是一种新型的纳米加工技术,但由于飞秒激光和金属的光热效应会产生激光烧蚀现象,难以直接在金属上实现高质量图案转移。结合飞秒激光直写技术和剥离(lift-off)工艺,开发了一种新型金属图案转移技术,可成功实现亚微米精度(0.89μm)的金属图案转移。探究了飞秒激光直写参数及显影方式和参数等对金属转移性能的影响。研究发现,随着飞秒激光曝光剂量的增加,金属转移精度有所提高。同时,干法显影效果优于湿法显影效果,且随着牺牲层显影时间的增加,转移线宽逐渐增大,但线条的粗糙度得到改善。在金属转移工艺中,通过设计并引入一定的底切角度,成功改善了金属线条的边缘翘曲和粗糙度高的现象。结合飞秒激光直写技术和lift-off工艺实现了直径为2 inch(1 inch=2.54 cm)的铬基转移光栅,并验证了制备的铬图案作为掩模板曝光的可行性,实现了SU-8光刻胶上的投影曝光,证明了所提策略局部替代电子束光刻进行掩模板加工的潜力。此外,基于该策略实现了Au和Pt的图案转移,说明所提策略具有一定普适性。Objective Femtosecond laser direct writing is a new nanofabrication technology.However,achieving high-quality pattern transfer directly on metal surfaces is difficult owing to the photothermal effect between the femtosecond laser and metal,which can result in laser ablation.To address this,we develop a new metal pattern transfer technology that combines femtosecond laser direct writing technology and the lift-off process.This technology enables precise metal pattern transfer at a sub-micron level(0.89μm).We explore the effects of femtosecond laser direct writing parameters and development methods and parameters on the performance of metal transfer.We observe that the accuracy of metal transfer increases with higher femtosecond laser exposure doses.Meanwhile,the dry development method outperforms the wet development method.Increasing the development time of the sacrificial layer results in a gradual increase in the transfer line width,accompanied by improved roughness of the line.By incorporating a specific undercut angle in the metal transfer process,we successfully address the edge warpage and high roughness of the metal lines.In this study,a chromium-based transfer grating with 2 inch(1 inch=2.54 cm)diameter is fabricated using the new approach.Additionally,the feasibility of using the prepared chromium pattern as a mask plate is verified using projection exposure on SU-8 photoresist,thus demonstrating the potential of the strategy to locally replace the e-beam lithography for mask plate processing.In addition,Au and Pt patterns are successfully transferred using this approach,demonstrating its universality and wide range of potential applications.Methods The lift-off process based on femtosecond laser processing comprises sample preparation,femtosecond laser exposure,development,sputtering of metal,and stripping.1)Sample preparation:The quartz substrate is cleaned using an ultrasonic machine and vacuum plasma machine to remove impurities.Thereafter,a sacrificial layer is spin-coated onto the quartz substrate

关 键 词：激光技术 飞秒激光直写 剥离工艺 金属图案化 掩模板加工 光刻胶 

分 类 号：TN305.7[电子电信—物理电子学]