Dielectric Charging Characterization of Triboelectric Effects in MEMS Switches

Dielectric charging is one of the key topics concerning microelectromechanical capacitive switch reliability; however, very little is known about how charge is generated on an exposed dielectric surface when brought in contact with another dielectric surface under high electric field. In this paper, we analyze and propose a model of surface charge generation of a microelectromechanical device produced by triboelectric effects under high electric field. A simplified theory has been developed that can be used either for electron or ion transfer, where a closed-form analytical solution is achieved under certain conditions. Measurements were performed during continuous hold-down stresses under different voltages and temperatures. The results based on pull-in voltage shift were fit using a MATLAB program where surface dielectric properties were extracted. The results show a qualitative agreement with the developed theory, and the extracted parameters can help to understand and predict the product reliability, as well as define a fabrication process screening procedure. [2015-0268]