Proceedings ArticleDOI
Metal contact reliability of RF MEMS switches
Qing Ma,Quan Tran,Tsung-Kuan A. Chou,John Heck,Hanan Bar,Rishi Kant,Valluri R. Rao +6 more
- Vol. 6463, pp 646305
TLDR
In this article, a collapsing switch capable of generating large contact forces (>300μN) was shown to be less vulnerable to contamination and stiction than a simple reed switch.Abstract:
It is well-recognized that MEMS switches, compared to their more traditional solid state counterparts, have several
important advantages for wireless communications. These include superior linearity, low insertion loss and high
isolation. Indeed, many potential applications have been investigated such as Tx/Rx antenna switching, frequency band
selection, tunable matching networks for PA and antenna, tunable filters, and antenna reconfiguration. However, none of
these applications have been materialized in high volume products to a large extent because of reliability concerns,
particularly those related to the metal contacts. The subject of the metal contact in a switch was studied extensively in
the history of developing miniaturized switches, such as the reed switches for telecommunication applications. While
such studies are highly relevant, they do not address the issues encountered in the sub 100μN, low contact force regime
in which most MEMS switches operate. At such low forces, the contact resistance is extremely sensitive to even a trace
amount of contamination on the contact surfaces. Significant work was done to develop wafer cleaning processes and
storage techniques for maintaining the cleanliness. To preserve contact cleanliness over the switch service lifetime,
several hermetic packaging technologies were developed and their effectiveness in protecting the contacts from
contamination was examined. The contact reliability is also very much influenced by the contact metal selection. When
pure Au, a relatively soft metal, was used as the contact material, significant stiction problems occurred when clean
switches were cycled in an N 2 environment. In addition, various mechanical damages occurred after extended switching
cycling tests. Harder metals, while more resistant to deformation and stiction, are more sensitive to chemical reactions,
particularly oxidation. They also lead to higher contact resistance because of their lower electrical conductivity and
smaller real contact areas at a given contact force. Contact reliability issues could also be tackled by improving
mechanical designs. A novel collapsing switch capable of generating large contact forces (>300μN) was shown to be
less vulnerable to contamination and stiction.read more
Citations
More filters
Journal ArticleDOI
Breakdown and Healing of Tungsten-Oxide Films on Microelectromechanical Relay Contacts
Ethan Falicov,Jessica Marvin,Zhixin Alice Ye,Sergio Almeida,Daniel S. Contreras,T.-J. King Liu,Matthew Spencer +6 more
TL;DR: In this article , the breakdown and healing of tungsten oxide films were investigated in microelectro-mechanical relays, and the reduction in contact current with time follows a power law, which is characteristic of charge relaxation in oxides.
Journal ArticleDOI
Analysis of Au metal–metal contacts in a lateral actuated RF MEMS switch
TL;DR: In this paper, the authors report on the ohmic contacts of an RF MEMS switch, and the most significant performance data are reported, indicating very low actuation voltage below 5V, switching time of
Proceedings ArticleDOI
Reliability enhancement of Ohmic RF MEMS switches
Steffen Kurth,Stefan Leidich,Andreas Bertz,M. Nowack,Jörg Frömel,Christian A. Kaufmann,Wolfgang Faust,Thomas Gessner,Akira Akiba,Koichi Ikeda +9 more
TL;DR: In this paper, the capacitively actuated Ohmic switches in series single pole single throw (SPST) configurations were evaluated for a frequency range from DC up to 80 GHz.
Journal ArticleDOI
Comparative study of RF MEMS micro-contact materials
Adrien Broué,Jérémie Dhennin,Pierre-Louis Charvet,Patrick Pons,Nourredine Ben Jemaa,P. Heeb,Fabio Coccetti,Robert Plana +7 more
TL;DR: In this paper, a comparison between several pairs of contact materials based on an innovative methodology early developed at NOVA MEMS is presented, which exploits a commercial nanoindenter coupled with electrical measurements, and test vehicles specially designed to investigate the underlying physics driving the surface-related failure modes.
Dissertation
Development and improvement of embedded structures in microelectronic chips : Study of mechanical and electrical contact
TL;DR: In this article, the authors integrate a MEMS within the same metal interconnect of CMOS layer, which, by rotating, can establish an electrical contact with a low resistance.
References
More filters
Journal ArticleDOI
Study of contacts in an electrostatically actuated microswitch
Sumit Majumder,Nicol E. McGruer,George G. Adams,P.M. Zavracky,Richard H. Morrison,Jacqueline Krim +5 more
TL;DR: In this paper, a clean metal contact resistance model was used to study the contact resistance of microswitches with gold contacts, and the measured contact resistance (measured as a function of contact force) with the characteristics predicted by the model showed approximate agreement.
Proceedings ArticleDOI
Conduction Properties of Microscopic Gold Contact Surfaces
TL;DR: In this paper, an interface force microscope (IFMIMM) was used to measure contact currents from 10 fA to 10 mA and forces ranging from 0.01 to 100 N. Both attractive and repulsive forces on the probe tip were found to exist at significant distances (greater than 5 nm) from the gold surface.
Journal ArticleDOI
Influence of physical/chemical characteristics of organic vapors and gas mixtures on their contact compatibility
TL;DR: In this paper, the contact compatibility of an organic vapor in combination with a certain contact material depends mainly on its chemical structure and its volatility, volatility, the basic structure type of the molecule (e.g., aromatic or aliphatic, length of the carbon chain), certain active groups on the other hand.
Proceedings ArticleDOI
Ceramic Via Wafer-Level Packaging for MEMS
TL;DR: Ceramic via wafer-level packaging of MEMS switches using eutectic gold-tin solder as well as tin-silver-copper solder combined with gold thermo-compression bonding is presented in this paper.
Journal ArticleDOI
Switching with the mercury-wetted-contact relay
TL;DR: The true essence of worth in any component (electrical, mechanical or solid state) can be illustrated by the length of time the particular device has been in use as discussed by the authors, which is the main reason why industry will continue to use components of proven reliability in many applications unless the new product demonstrates clearly its superiority in a number of spheres-cost, reliability, size, availability etc.