Micro-Fabricated Electrostatic Voltage Sensor with a Thin Bulk-Silicon Device Layer
J. Dittmer, R. Judaschke, S. Büttgenbach
Technische Universität Braunschweig, DE
Keywords: rf mems, rms sensor, soi, batch process
Abstract:Micro-fabricated sensors made of a 20 µm thick bulk-silicon device layer for electrostatic voltage measurements are presented. A rotational, seesaw-like actuator with two electrically isolated electrodes on its ends forming parallel-plate capacitors with opposing electrodes in close proximity. When a voltage is applied between a pair of electrodes, the plate is subjected to a force proportional to the square of the applied voltage, causing it to turn to an equilibrium position with the restoring spring force of the suspension. From the measured position the original voltage can be calculated or compared with the displacement of a known reference voltage. Fabrication process and measurement results are presented and related to the theory.