Determination of bulk discharge current in the dielectric film of MEMS capacitive switches

The present work presents a new method to calculate the discharge current in the bulk of dielectric films of MEMS capacitive switches. This method takes into account the real MEMS switch with non uniform trapped charge and air gap distributions. Assessment of switches with silicon nitride dielectric film shows that the discharge current transient seems to obey the stretched exponential law. The decay characteristics depend on the polarization field’s polarity, a fact comes along with experimental results obtained from thermally stimulated depolarization currents (TSDC) method used in MIM capacitors

Properties of contactless and contacted charging in MEMS capacitive switches

The dielectric charging in MEMS capacitive switches is a complex effect. The high electric field during pull-down causes intrinsic free charge migration and dipole orientation as well as charge injection. The macroscopic dipole moment of the first two mechanisms is opposite to the one arising from charge injection. This causes partial compensation hence mitigates the overall charging and increases the device lifetime. The charging due to intrinsic free charge migration and dipole orientation can be monitored under contactless electric field application in the pull-up state. The paper investigates the characteristics of contactless charging and compares them with the ones of contacted charging. The characteristics of the discharging process that follows each charging procedure are also presented

Field emission induced-damage in the actuation paths of MEMS capacitive structures

The field emission and resulting breakdown induced damage in the actuation paths of MEMS capacitive switches are investigated. The effect of asperities burning due to Joule heating and the resulting explosive break down are presented. The breakdown gives rise to almost mirror craters formation on the cathode and anode electrodes. A linear relation between crater diameter and the breakdown current is found when breakdown occurs in vacuum. In ambient atmosphere the breakdown leads to large amplitude current oscillations and the formation of extended damage on both electrodes. © 2020 Elsevier Lt

Investigation of charging processes in dielectrics for RF mems capacitive switches

The charging processes have been investigated in dielectrics used in RF MEMS capacitive switches. The investigation included various silicon oxides and nitrides. Finally, the effect of substrate, bottom electrode, has been taken into account

Investigation of Charging Processes in Dielectrics for RF MEMS Capacitive Switches

The charging processes have been investigated in dielectrics used in RF MEMS capacitive switches. The investigation included various silicon oxides and nitrides. Finally, the effect of substrate, bottom electrode, has been taken into account

Floating electrode microelectromechanical system capacitive switches: A different actuation mechanism

The paper investigates the actuation mechanism in floating electrode MEMS capacitive switches. It is demonstrated that in the pull-in state the device operation turns from voltage to current controlled actuation. The current arises from Poole-Frenkel mechanism in the dielectric film and Fowler-Nordheim in the bridge-floating electrode air gap. The pull-out voltage seems to arise from the abrupt decrease of Fowler-Nordheim electric field intensity. This mechanism seems to be responsible for the very small difference with respect to the pull-in voltage

Dielectric charging phenomena in diamond films used in RF MEMS capacitive switches: The effect of film thickness

The present paper aims to provide a better insight to the dielectric charging phenomena of nano-crystalline diamond (NCD) films that are used in RF MEMS capacitive switches. The electrical properties of NCD films of various thicknesses are investigated with the aid of metal-insulator-metal (MIM) capacitors. The dominant conduction mechanisms have been identified by obtaining current-voltage characteristics in the temperature range from 300 K to 400 K and dielectric charging phenomena have been investigated by using thermally stimulated depolarization currents (TSDC) technique. The experimental results indicate a thermally activated conductivity for low electric field intensities while Hill-type conduction takes place for field intensities > 130 kV/cm. The conductivity as well as the defect density seems to increase with film thickness. Enhanced dielectric charging phenomena have been observed on thicker films and the injected charges are found to be trapped through the material's volume. These results indicate that thinner NCD films seem to be more promising for RF MEMS capacitive switches. © 2016 Elsevier Lt

Floating electrode microelectromechanical system capacitive switches: A different actuation mechanism

The paper investigates the actuation mechanism in floating electrode MEMS capacitive switches. It is demonstrated that in the pull-in state the device operation turns from voltage to current controlled actuation. The current arises from Poole-Frenkel mechanism in the dielectric film and Fowler-Nordheim in the bridge-floating electrode air gap. The pull-out voltage seems to arise from the abrupt decrease of Fowler-Nordheim electric field intensity. This mechanism seems to be responsible for the very small difference with respect to the pull-in voltage

Electrical characteristics of floating electrode MEMS capacitive switches

The present paper investigates in depth the electrical behaviour of floating electrode MEMS switches when their actuation is performed through the transmission line. The study is carried out through modeling and experimentally obtained capacitance- and current-voltage characteristic. It is demonstrated for the first time that constant down state capacitance is achieved without contacting the floating electrode with the moving armature. Moreover the pull-in and pull-out conditions are discussed in details