基于lift-off工艺的RF MEMS开关触点平坦化方法  

Planarization Method for Contact of RF MEMS Switch Based on Lift-Off Process

作　　者：杨彪 诸葛明华 吴国才 容炎森 Yang Biao;Zhuge Minghua;Wu Guocai;Rong Yansen(College of Integrated Circuits and Optoelectronic Chips,Shenzhen Technology University,Shenzhen 518118,China;Integrated Optoelectronic Engineering Center,Shenzhen Technology University,Shenzhen 518118,China)

机构地区：[1]深圳技术大学集成电路与光电芯片学院,广东深圳518118 [2]深圳技术大学集成光电子工程中心,广东深圳518118

出　　处：《微纳电子技术》2025年第2期116-121,共6页Micronanoelectronic Technology

基　　金：国家自然科学基金青年基金(62105082);广东省基础与应用研究基金(2023A1515011257);深圳市科技计划资助项目(20231129092735001)。

摘　　要：采用表面微加工工艺制备射频微机电系统(RF MEMS)开关,开关触点的平坦化是一项关键工艺,直接影响RF MEMS开关的机械和电学性能。设计静电驱动接触式的RF MEMS开关结构,然后通过在触点上进行套刻制备光刻胶岛、蒸镀制备铝牺牲层,利用lift-off工艺解决触点与牺牲层平坦化的问题。再采用电镀工艺制备金悬臂梁,使用氢氧化钠溶液腐蚀铝释放获得RF MEMS开关。通过原子力显微镜(AFM)、聚焦离子束显微镜(FIB)等仪器对样品进行形貌测量,数据显示开关触点与铝牺牲层的高度差约为27.36 nm,悬臂梁与下方平面的左右空隙差约为22 nm,结果表明通过该方法能够实现开关触点与牺牲层的高度平坦化。The contact planarization is an important process in fabricating radio frequency microelectromechanical system(RF MEMS)switch using surface micro-fabrication techniques,which directly affects the mechanical and electrical performance of the RF MEMS switch.The structure of electrostatic actuated RF MEMS switch with contact-type was designed.Then the lift-off process was used to solve the issue of planarization between the contacts and the sacrificial layer,in which a cylindrical photoresist island was overlaid on the contacts of RF MEMS switch,and subsequently,an aluminum(Al)film was deposited as a sacrificial layer by evaporation system.Next,the gold cantilever beam was fabricated by an electroplating process,and the Al film was wet etched through sodium hydroxide solution.Finally,the RF MEMS switch was released and obtained.The surface morphologies of the samples were measured by instruments such as atomic force microscopy(AFM)and focused ion beam microscopy(FIB).The data show that the height difference between the switch contacts and the Al sacrificial layer is approximately 27.36 nm,and the difference in the gap between the left and right sides of the cantilever beam and the lower flat is about 22 nm.The results indicate that the high planarization between the switch contacts and the sacrificial layer can be achieved by this method.

关 键 词：射频微机电系统(RF MEMS)开关 开关触点 牺牲层 平坦化 lift-off工艺 

分 类 号：TN305.2[电子电信—物理电子学] TH703[机械工程—仪器科学与技术]