Arbitrary Shaped Backside Reinforcement for Two Dimensional Resonant Micromirrors

This paper reports a backside reinforcement technique for two-dimensional resonant scanning mirrors. The backside reinforcement patterns are generated based on the product of the surface stress and the distance from the rotation axis of interest, and the patterns are combined for both axes. The piezoelectrically actuated two-dimensional micromirrors were fabricated inhouse. The novel fabrication approach makes it possible to obtain backside reinforcement of any desired thickness. It has been experimentally proven that the deformation is reduced by more than 50% for torsion mode and 40% for rocking mode without a significant increase in the moment of inertia: 3% and 9%, respectively.