Micromechanical structures having a capacitive transducer gap filled with a dielectric and method of making same

Abstract

Micromechanical structures having at least one lateral capacitive transducer gap filled with a dielectric and method of making same are provided. VHF and UHF MEMS-based vibrating micromechanical resonators filled with new solid dielectric capacitive transducer gaps to replace previously used air gaps have been demonstrated at 160 MHz, with Q's˜20,200 on par with those of air-gap resonators, and motional resistances (R's) more than 8× smaller at similar frequencies and bias conditions. This degree of motional resistance reduction comes about via not only the higher dielectric constant provided by a solid-filled electrode-to-resonator gap, but also by the ability to achieve smaller solid gaps than air gaps. These advantages with the right dielectric material may now allow capacitively-transduced resonators to match to the 50-377Ω impedances expected by off-chip components (e.g., antennas) in many wireless applications without the need for high voltages.