Research of the influence of technological parameters on the electrophysical characteristics of the RF MEMS switch

Abstract

Effective design of micromechanical switches for operation in various frequency ranges is impossible without mathematical models including the correlation of electrophysical parameters with the design and technological parameters of their fabrication. This task is complicated by the fact that different technologies and materials are used to create RF MEMS switch. An earlier analysis of the creation of the MEMS switch allowed us to identify groups of factors that have a significant impact on the electrophysical and frequency characteristics. To assess the influence of technological factors on the electrophysical and frequency properties, technological parameters such as the etching time of various layers, the processing temperature, and material properties such as electrical conductivity, Young's modulus, permittivity, and electrical resistivity were selected. And as design parameters, changes in thickness during the formation of the dielectric layer and the membrane, the thickness of the gap between the membrane and the dielectric layer were considered. In this paper, we construct a MEMS switch model including the influence of design and technological parameters on the characteristics of the switch in the on and off state. Another task is to assess the impact of technological uncontrolled effects that occur under certain conditions in the fabrication of a switch. Electrodynamic modeling of the switch was performed by the finite element method using the mathematical model that includes design and technological parameters. The operation voltage, switching time, the frequency of natural vibrations of the membrane, and the voltage characteristic of the switch were studied. The mathematical model of a micromechanical switch, including the technological parameters of its fabrication, will allow developing technological processes for the fabrication of MEMS switches that match the requirements in the specified frequency ranges and have low losses.