三层多晶硅结构的挠曲式静电驱动MEMS微反射镜  

Curved Electrostatic Actuation MEMS Micro-Reflector with Three-Layer Polysilicon Structure

作　　者：吴嘉琦 赖丽燕 李以贵 Wu Jiaqi;Lai Liyan;Li Yigui(School of Science,Shanghai Institute of Technology,Shanghai 201418,China)

机构地区：[1]上海应用技术大学理学院,上海201418

出　　处：《微纳电子技术》2023年第9期1436-1444,共9页Micronanoelectronic Technology

基　　金：国家自然科学基金(62104151);上海应用技术大学引进人才基金项目(YJ2021-59)。

摘　　要：将悬臂梁结构与平行平板型结构相结合,研发了一种挠曲式静电驱动微电子机械系统(MEMS)微反射镜。为了实现大扭转角度、小驱动电压的设计目标,通过仿真实验进行对比分析,确定了微反射镜的相关尺寸。采用低压化学气相沉积、光刻、反应离子刻蚀和溅射等工艺,成功制备出了一种具有三层多晶硅结构的微反射镜。在制备过程中得出氢氟酸去除牺牲层(磷硅玻璃)释放出微反射镜结构的最佳刻蚀时间为45 s。制作了开关频率为200 kHz的MOSFET高速驱动电路,电路中的栅极驱动电阻(R_(G))是影响输出的关键因素。实验结果表明,当R_(G)额定功率为300 W、电阻为47Ω时,微反射镜能够达到足够启动速度,实现高速开关的设计目标。最后,设计并搭建了微反射镜的测试系统,施加60 V的驱动电压进行测试,通过显微镜观察到微反射镜的明显动作变化以及屏幕上光斑的位移变化,表明制备的微反射镜可正常驱动。A curved electrostatic actuation micro-electromechanical system(MEMS)microreflector was developed by combining a cantilever beam structure with a parallel plate structure.To achieve the design goals of large torsion angle and low driving voltage,comparative analysis was conducted through simulation experiments to determine the relevant dimensions of the microreflector.A micro-reflector with three-layer polysilicon structure was successfully fabricated by using processes such as low-pressure chemical vapor deposition,photo-lithography,reactive ion etching and sputtering.During the preparation process,it is found that the optimal etching time of hydrofluoric acid to remove the sacrificial layer(phosphorus silicon glass)and release the micro-reflector structure is 45 s.A high-speed driving circuit based on MOSFETs with a switching frequency of 200 kHz was fabricated.The driving resistor of the gate(R_(G))in the circuit is a key factor affecting the output.The experimental results show that when the R_(G) rated power is 300 W and the resistance is 47Ω,the micro-reflector can achieve sufficient startup speed,achieving the design goal of high-speed switching.Finally,a testing system of the microreflector was designed and built,and a driving voltage of 60 V was applied for testing.The obvious movement of the micro-reflector and the displacement of the light spot on the screen were observed by a microscope,confirming that the prepared micro-reflector can be driven normally.

关 键 词：微机电系统(MEMS) 微反射镜 静电驱动 悬臂梁式 平行平板型 

分 类 号：TH703[机械工程—仪器科学与技术]