Center-Shift Method for the Characterization of Dielectric Charging in RF MEMS Capacitive Switches

Abstract

Abstract-Radio frequency (RF) micro-electro-mechanical systems (MEMS) capacitive switches show great promise for use in wireless communication devices such as mobile phones, but for the successful application of these switches their reliability needs to be demonstrated. One of the main factors that limits the reliability is charge injection in the dielectric layer (SiN) which can cause irreversible stiction of the moving part of the switch.We present a way to characterize charge injection. By stressing the dielectric with electric fields on the order of 1 MV/cm, we inject charge in the dielectric and measure the effects it has on the curve. Instead of conventionally measuring the change of the pull-in voltage, the presented center shift method measures the change of the voltage at which the capacitance is minimal. This way, the measurement method does not influence the charge injected by the stress voltage. Another advantage is that the measurement of the amount of injected charge is not influenced by changes in the width of the curve. These two advantages make it possible to test RF-MEMS capacitive switches in a more accurate way.

Simultaneous Control of Dielectric Charge and Device Capacitance in Electrostatic MEMS

“…Capacitance measurements performed at symbol times (1 − δ)T S and T S allow to obtain the quasi-differential capacitance ∆C = C + − C − , where C + and C − are the device capacitances measured when applying V + and V − , respectively. Taking into account that for voltages below pull-in the C-V can be approximated by a parabolic function [3], [9], V sh can be obtained at t = nT S as:…”

Optimal condition of memristance enhancement circuit using external voltage source

“…1, 2 Properties of memristive devices, such as memristors, 2-10 memcapacitors, [11][12][13][14] and meminductors, 15 depend on the history and state of the systems. Such memristive devices have opened up numerous potential applications; digital memories, [16][17][18][19][20] logic circuits, 21 neuromorphic circuits, [22][23][24] learning circuits, 25 programmable circuits, 26 and sensors.…”

Temperature dependent actuation voltage for longer MEMS switch lifetime

“…C-V curve of capacitive RF MEMS switch before (solid line) and after continuous actuation (dotted line)[8].…”