Passivated Piezoresistive Rotation Angle Sensor Integrated in Micromirror

A piezoresistive rotation angle sensor integrated in a micromirror device is improved with the passivation film. The sensor detects the shear stress inside the torsion bar generated by the mirror rotation under the electrostatic driving. The rotation angle is measured during the actuation. The passivation film reduces the leak current. The sensor signal shows the better performance showing the smaller hysteresis.