Dielectric charging in microwave microelectromechanical Ohmic series and capacitive shunt switches

Abstract

The charging of the dielectric used for the actuation in microelectromechanical system (MEMS) devices is one of the major failure sources for switches based on this technology. For this reason, a better understanding of such an effect is vital to improve the reliability for both ground and space applications. In this paper, the expected response of MEMS switches to unipolar and bipolar dc actuation voltages has been measured and modeled. Two configurations of MEMS switches, namely, an Ohmic series and a shunt capacitive one designed for microwave applications, have been studied as a test vehicle for charging effects related to the dc actuation pads. The recorded data have been interpreted mainly through the Poole–Frenkel effect due to charge injection when a high voltage is applied to the dielectric layer. Metal-Insulator-Metal (MIM) structures have been also considered as a complementary information for the response of the dielectric material.

Integrated Magnetic MEMS Relays: Status of the Technology

“…This is one of the reasons why work is underway with the aim of reducing the actuation voltage requirements for new devices [21,[44][45][46][47] and designing optimised actuation waveforms [59][60][61][62] for minimal dielectric charging.…”

Dynamics of RF Micro-Mechanical Capacitive Shunt Switches in Coplanar Waveguide Configuration

“…From the above Eq (31), simple considerations can be anticipated about the contribution of charging processes and possible sticking of the bridge. It is known that successive applications of the voltage correspond to an accumulation of charge in the dielectric and in an increase of the actuation voltage [43], with an asymptotic trend up to its maximum value [44], [45]. In fact, if it is not given time enough to the charges to be dissipated, they grow up to the maximum contribution allowed by the geometry and by the properties of the dielectric material used for the capacitive response (in the case of central actuation) or by the dielectric used for the actuation pads (lateral actuation).…”

Reliability of RF MEMS capacitive and ohmic switches for space redundancy configurations

“…The interdisciplinary skill typical of MEMS manufacturing has been enriched by the necessity of additional considerations in terms of high frequency design, technology and reliability in harsh environment, even including mechanical analysis [1][2] [3] and charging effects [4][5] [6].…”