Low cost polymer MEMS mirrors fabricated by photolithography and wet etching processes

This paper presents two types of low cost mirror devices composed of the glass and the polymer material. These devices are new constructions composed of the inexpensive glass as the mirror substrate and the polymer as the torsion hinge. The devices can be fabricated by the photolithography and wet etching processes without deep-RIE process. The proposed one construction is the Lorentz force type mirror device made of polyimide material. And the other construction is the electromagnet force type mirror device made of SU-8 material containing the magnetic particles. In the former type mirror, the mirror device was fabricated without expensive dry etching equipment such as RIE, and the device can be fabricated only by the sputtering, photolithography and wet etching processes. Further, the inexpensive glass and polymer material are used instead of expensive Si. In the latter type mirror, the SU-8 polymer material containing the magnetic particles is used. The actuation system which attracts the mirror directly with the electromagnet is adopted. We fabricated the large-sized mirror (20 mm times 10 mm) device without expensive dry etching equipment such as deep-RIE, and evaluated the characteristics of the fabricated mirror device. The optical deflection angle of plusmn20 deg. was achieved. As the result, we confirmed the feasibility to realize the low cost polymer MEMS mirror.