Diamond shaped frame supported electrostatic scanning micromirror

The paper presents the design, fabrication and measurement of an electrostatic scanning micromirror having a diaphragm mirror plate supported by an array of diamond shaped frame structures. Instead of supporting the diaphragm mirror of a different material with a stiff rim structure at the circumference, the diaphragm mirror plate and the frame structure are fabricated monolithically in the same layer of single-crystal-silicon (Nee, J.T. et al., Proc. IEEE Int. Conf. MEMS, p.704-9, 2000). The scanning micromirror with a 10 μm-thick diaphragm mirror plate, having a planar dimension of 1.5×1.5 mm², supported by an array of 110 μm-thick rhombic stiffening frames, was fabricated and tested. A mechanical deflection angle of 8.5° at the resonance frequency of 19.55 kHz and 44% reduction of dynamic deformation (Conant, R.A. et al., Proc. IEEE/LEOS Int. Conf. Optical MEMS, p.49-50, 2000), in comparison to the conventional rectangular parallelepiped micromirror, were obtained.