Design, realization and testing of micro-mechanical resonators in thick-film silicon technology with postprocess electrode-to-resonator gap reduction

Abstract

This paper presents the design, fabrication and testing of high-Q high-frequency lateral-mode clamped–clamped beam micro-resonators driven by parallel-plate electrostatic transducers fabricated in a thick epipoly technology. An innovative approach is employed to reduce an intrinsically high transducer gap value (>3.0 μm) required by the need of 15 μm thick structural layer etching down to 0.2–0.4 μm after the fabrication. This is achieved by employing an electrostatic motor that approaches the actuating and sensing electrodes close to the resonator. The electrode motor is driven with 30 V dc voltage, without any dc current consumption. Two resonators having a resonance frequency of 10 MHz have been fabricated with gap values of 0.2 and 0.4 μm respectively. A comparative analysis of performances of the two resonators is given in the paper.