Fabrication and Characterization of a Novel Piezoelectric MEMS Mirror with High Fill Factor and High Speed

This paper reports the verification of a novel piezoelectric MEMS mirror, which utilizes a three-level-construction comprising a mirror plate, three pairs of pillar and actuator hidden beneath the mirror plate, achieving the high fill factor (>90%) and high speed (~20KHz). The novel structure of three folded springs embedded in the back of the mirror plate is fabricated by unique microhole inter-etch and sealing (MIS) process to reduce stress. Moreover, AlScN piezoelectric film is applied to increase deflection, as well as benefits like compatible with CMOS process, great linearity and long-term stability. We finally demonstrate the design of the MEMS mirror with high fill factor and high speed.