Design and Fabrication Method of a Large-Size Electromagnetic MEMS Two-Dimensional Scanning Micromirror

This paper proposes a design and fabrication method to address the technical challenges associated with the design and fabrication of large-size Micro Electro Mechanical Systems (MEMS) two-dimensional scanning micromirrors. The method employs the Lagrangian energy method to establish a kinetic model for the micromirror and utilizes the material mechanics method to analyze the structural parameters. Building upon the aforementioned theoretical framework, a large-size electromagnetic MEMS two-dimensional scanning micromirror is designed and fabricated by incorporating a stiffener structure on its back to enhance its surface rigidity. Furthermore, a novel MEMS micromirror process is developed based on silicon wafers, which effectively enhances the surface flatness and yield rate of the large-size MEMS micromirror. The fabricated MEMS two-dimensional scanning micromirror has an effective mirror size of 5-mm $\times7$ -mm. The experimental results demonstrate that the proposed method is effective, as evidenced by the resonant frequencies of the slow-axis and fast-axis of the micromirror at 365-Hz and 1650-Hz, respectively, and the corresponding quality factors of 73 and 413. Moreover, the micromirror achieved scanning angles of 23.4° and 10.4°, respectively, when driven by a 5-V voltage, validating the design and fabrication approach. [2023-0115]