Effect of substrate charging on the reliability of capacitive RF MEMS switches

Physics of Charging in Dielectrics and Reliability of Capacitive RF-MEMS Switches

“…The nowadays available information clearly proves the presence of two types of charges, which is responsible for the shift of capacitance-voltage characteristic. The presence of opposite polarity carriers is responsible for the shift C-V characteristic in voltage and capacitance domain, a behavior has been predicted (Rottenberg 2007) and shown experimentally , Czarnecki 2008). Moreover, the charging, when occurs with the switch in the down state, arises from the Poole-Frenkel transient current component, which gives rise to time and electric field dependent dielectric charging .…”

“…The presence of two different types of charges, which are responsible for the dielectric charging, has been confirmed by experiments using either positive or negative actuation voltage (Czarnecki 2008). The conclusion was drawn from the behavior of pull-in and pullout windows immediately after stress as well as after 1 min after stress ( fig.12) www.intechopen.com Here it must be pointed out that these results confirm the predictions of [9.39] and are supported from previous publications and (Papaioannou 2007a) as well as recent ones (Olszewski 2008) where the existence of two types of charges, which contribute to dielectric charging, has been reported.…”

“…www.intechopen.com These charging mechanisms in addition to the non planar dielectric film and bridge surfaces lead to a charge distribution that determines the switch behavior (Rottenberg 2008). This non uniform charge distribution has been monitored through measurements of surface potential on a capacitive switch dielectric with the aid of KPFM ( fig.9) .…”

“…The dependence of switches lifetime on the environmental gas and the gas pressure have been recently investigated (Blondy 2007, Czarnecki 2008. Although it is well understood that gasses interact with the dielectric free surface the mechanism that affects the charge storage, hence the dielectric charging, is still not understood.…”

Glass polarization induced drift in microelectromechanical capacitor

“…Recently, Czarnecki et al noticed that the narrowing of the pull-out window is related to the substrate the device is fabricated on. 7 Especially an RF switch on glass substrate was prone to inhomogeneous charging. 7 The authors used finite element simulations 7,8 for analyzing the effect of substrate charges, but they did not provide the physical mechanism for the charging of the glass substrate.…”