Dielectric charging in capacitive microelectromechanical system switches with silicon nitride

The paper attempts to elaborate on the basic problem of dielectric charging in insulating films for microelectromechanical capacitive switches, the dependence of the film electrical properties on material stoichiometry and the uncertainty of whether the implementation of a leaky dielectric would reduce the charging effects. Silicon nitride films with stoichiometries (N/Si) ranging from 0.36 to 0.85 were assessed in metal-insulator-metal capacitors using the thermally stimulated depolarization current method and by obtaining the current-voltage characteristics. Capacitive switches were also fabricated with the same dielectric films. Results from both devices revealed an enhanced charging in the case of silicon-rich films. (C) 2011 American Institute of Physics. [doi:10.1063/1.3560465]