MEMS静电驱动微镜阵列的设计与工艺研究

Design and process study of MEMS electrostatic-actuated micromirror array

基于微机电系统(MEMS)工艺,设计并制作了一种应用于光通信领域的二维准静态驱动微镜阵列(MMA)。相比于梳齿驱动,平行板电容式静电微镜更易于形成高占空比的阵列排布,有利于作为光开关矩阵应用在全光交换中。通过设计弹性系数小的“竖蛇形”双扭转轴结构,有效降低了微镜的驱动电压;并采用硅—玻璃阳极键合工艺来实现平板电容结构,将绝缘的玻璃作为电极基底与绝缘体上硅(SOI)硅器件层键合,不仅实现了良好的电隔离,提高了器件的稳定性,且能很好地与阵列扩展兼容。制备出的1×4微镜阵列可实现X/Y方向的二维(2D)准静态驱动,测试结果与有限元仿真结果基本吻合。结果表明,微镜内、外轴可分别在26.5V和29.5V的直流电压驱动下达到±2°机械转角,微镜响应时间为5ms。

Based on MEMS processing,a 2D quasi-static driven micromirror array(MMA)used in optical communication field is designed and fabricated.Compared with the comb-drive micromirror,the electrostatic micromirror based on the parallel-plate capacitor is easier to form a high duty-factor array arrangement,which is beneficial to be used in all-optical switching as an optical switch matrix.By designing“vertical serpentine”biaxial torsion axis structure with a small coefficient of elasticity,effectively reduces the driving voltage of the micromirror,and the silicon-glass anodic bonding process is used to make the parallel plate capacitor structure,and the insulated glass is used as the electrode substrate to bond with the silicon device layer of a silicon on insulator(SOI)wafer,which not only achieves good electrical isolation,improves the stability of devices,but also is well compatible with the array expansion.The fabricated 1×4 micromirror array can realize 2-D quasi-static driving in the X/Y direction.The test results are approximately consistent with the finite element simulation results.The results show that the mechanical rotation angles of the inner and outer-axis of the micromirror can reach ±2°at a DC voltage of 26.5 V and 29.5 V,respectively,and the response time of the micromirror is 5 ms.