Capacitive and ohmic RF MEMS switches are based on micron‐sized structures moving under electrostatic force in a gaseous environment. Recent experimental measurements [4, 5] point to a critical role of gas‐phase effects on the lifetime of RF MEMS switches. In this paper, we analyze rarefied flow effects on the gas‐damping behavior of typical capacitive switches. Several damping models based on Reynolds equation [7, 8] and on Boltzmann kinetic equation [9, 6] are applied to quantify the effects of uncertainties in fabrication and operating conditions on the impact velocity of switch contact surfaces for various switch configurations. Implications of rarefied flow effects in the gas damping for design and analysis of RF MEMS devices are discussed. It has been demonstrated that although all damping models considered predict a similar damping quality factor and agree well for predictions of closing time, the models differ by a factor of two and more in predicting the impact velocity and acceleration at contact. Implications of parameter uncertainties on the key reliability‐related parameters such as the pull‐in voltage, closing time and impact velocity are also discussed.


Copyright (2011) American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in (A. Alexeenko and S. Chigullapalli, "Implications of Rarefied Gas Damping for RF MEMS Reliability", AIP Conf. Proc., Vol. 1333, 27th International Symposium on Rarefied Gas Dynamics, pp. 701-706, 2011.) and may be found at http://dx.doi.org/10.1063/1.3562728. The following article has been submitted to/accepted by [American Institute of Physics]. After it is published, it will be found at (http://dx.doi.org/10.1063/1.3562728). Copyright (2011) A. Alexeenko and S. Chigullapalli. This article is distributed under a Creative Commons Attribution 3.0 Unported License.

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