scholarly journals A seesaw-type MEMS switch with enhanced contact force: the first results

2021 ◽  
Vol 2086 (1) ◽  
pp. 012069
Author(s):  
I V Uvarov ◽  
N V Marukhin
Keyword(s):  
Contact Resistance ◽  
Contact Force ◽  
Microelectromechanical Systems ◽  
Actuation Voltage ◽  
Experimental Results ◽  
Mems Switches ◽  
Commercial Success ◽  
Mems Switch ◽  
First Results ◽  
Fast Increase

Abstract Outstanding working characteristics make microelectromechanical systems (MEMS) switches attractive for many applications. However, the lack of reliability prevents their commercial success. Due to the small size, MEMS switches develop low contact force compared to their macroscopic counterparts, which leads to instability and fast increase of the contact resistance. This work describes the switch providing significantly larger force than the previously reported device. The enlargement is achieved by the modified shape of the beam and electrodes with the same footprint and lower actuation voltage. Design, simulation, fabrication and first experimental results for the switch are presented.

The Influence of Ambient Pressure on the Dynamic Response of RF MEMS Switches

2010 ◽  
Author(s):  
Avihay Ohana ◽  
Oren Aharon ◽  
Ronen Maimon ◽  
Boris Nepomnyashchy ◽  
Lior Kogut
Keyword(s):  
Rf Mems ◽  
Ambient Pressure ◽  
Actuation Voltage ◽  
Operating Conditions ◽  
Experimental Results ◽  
Release Time ◽  
Q Factor ◽  
Optimal Operating ◽  
Mems Switches ◽  
Rf Mems Switches

A study of the dynamic behavior of an RF MEMS switch is presented at different operating conditions. Experimental results for the actuation and release time and Q-factor as a function of the ambient pressure and actuation voltage are compared to theoretical predictions based on existing model. Optimal operating conditions (ambient pressure and actuation voltage) are determined based on two criterions: minimal actuation and release time and minimal oscillations upon switch release. In light of the experimental results optimal operating conditions determined to be 1.4Vpi at a pressure of a few torrs where actuation and release time are equal and short enough with no release oscillations. Three pressure regimes are identified with characteristic behavior of the Q-factor and actuation and release time in each regime. These behaviors have significant implications in many MEMS devices, especially RF MEMS switches.

Automated and Optimal Actuation Voltage Waveform Design for Contact Bouncing Mitigation of MEMS Switches

2014 ◽  
Vol 609-610 ◽  
pp. 1248-1253
Author(s):  
Chen Xu Zhao ◽  
Xin Guo ◽  
Tao Deng ◽  
Ling Li ◽  
Ze Wen Liu
Keyword(s):  
Actuation Voltage ◽  
Waveform Design ◽  
Practical Case ◽  
Voltage Waveform ◽  
Mems Switches ◽  
Mems Switch ◽  
Simulation Based ◽  
Speed Up ◽  
Bouncing Effect

This paper presents an efficient methodology for automated optimal tailoring actuation voltage waveform of MEMS switches aiming at eliminating the detrimental contact bouncing effect to speed up the switching process and improve the mechanical reliability. This is a simulation-based approach where genetic algorithm (GA) is used in combination with a dedicated mechanical model of MEMS switch to derive optimal actuation waveform. The proposed technique has been implemented in SystemC-A, which is extremely well suited for complex modeling, implementation of post-processing of simulation results and optimization algorithms. Effectiveness of proposed approach is corroborated by a practical case study of automated actuation waveform design for a prefabricated DC-contact MEMS switch. The experimental results show that the switching time of the switch by employing optimized actuation voltage waveform is dramatically reduced to 60μs from 95μs, while the bouncing effect is successfully eliminated.

scholarly journals Low-Voltage and High-Reliability RF MEMS Switch with Combined Electrothermal and Electrostatic Actuation

Micromachines ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1237
Author(s):  
Yong Zhu ◽  
Jitendra Pal
Keyword(s):  
Microelectromechanical Systems ◽  
Rf Mems ◽  
Low Voltage ◽  
High Reliability ◽  
Actuation Voltage ◽  
Electrostatic Actuation ◽  
Mems Switch ◽  
Thermal Actuation ◽  
Electrothermal Actuation ◽  
Power Handling Capability

In this paper, we report a novel laterally actuated Radio Frequency (RF) Microelectromechanical Systems (MEMS) switch, which is based on a combination of electrothermal actuation and electrostatic latching hold. The switch takes the advantages of both actuation mechanisms: large actuation force, low actuation voltage, and high reliability of the thermal actuation for initial movement; and low power consumption of the electrostatic actuation for holding the switch in position in ON state. The switch with an initial switch gap of 7 µm has an electrothermal actuation voltage of 7 V and an electrostatic holding voltage of 21 V. The switch achieves superior RF performances: the measured insertion loss is −0.73 dB at 6 GHz, whereas the isolation is −46 dB at 6 GHz. In addition, the switch shows high reliability and power handling capability: the switch can operate up to 10 million cycles without failure with 1 W power applied to its signal line.

The Effect of Dielectric Charging on Capacitive MEMS Switch

2014 ◽  
Vol 511-512 ◽  
pp. 732-736
Author(s):  
Qin Wen Huang ◽  
Xiang Guang Li ◽  
Yun Hui Wang ◽  
Yu Bin Jia
Keyword(s):  
Rf Mems ◽  
Actuation Voltage ◽  
Deposition Process ◽  
Dielectric Surface ◽  
One Dimensional ◽  
Mems Switches ◽  
Dielectric Charging ◽  
Mems Switch ◽  
Rf Mems Switches ◽  
Capacitive Mems

Based on a one-dimensional model of dielectric charging for capacitive RF MEMS switches, the accumulated charge density and actuation voltage shift were simulated. The results illustrate that rougher surface can reduce dielectric charging, so the dielectric layer should be fabricated much rougher during deposition process. But the capacitance ratio of switch will be decreased with rougher surface, which can cause a reduction of switch performance. Thus the dielectric surface roughness should be balanced in reliability and isolation.

Film Stress Influence of Bilayer Metallization on the Structure of RF MEMS Switches

1999 ◽  
Vol 594 ◽  
Author(s):  
R. E. Strawser ◽  
R. Cortez ◽  
M. J. O'Keefe ◽  
K. D. Leedy ◽  
J. L. Ebel ◽  
...  
Keyword(s):  
Structural Integrity ◽  
Microelectromechanical Systems ◽  
Rf Mems ◽  
Actuation Voltage ◽  
Stress Gradient ◽  
Film Stress ◽  
Electrical Performance ◽  
Cantilever Beams ◽  
Mems Switches ◽  
Clamped Beams

AbstractThe performance of microelectromechanical systems (MEMS) switches is highly dependent on the switches' constituent materials. The switch material must be able to provide both structural integrity and high electrical conductivity. Cantilever beams, doubly clamped beams, and membranes are typical MEMS structures used in microwave/millimeter wave applications. In this study, cantilever and doubly clamped beam microswitches were fabricated on GaAs substrates using evaporated bilayers of titanium and gold metallization in which the total thickness was held constant at 1.5 μm while the gold thickness varied from 0.5 μm to 1.5 μm. The lengths of the cantilevers varied from 300 to 500 μm and the doubly clamped beams varied from 600 to 800 μm. An upward deflection of the gold dominated cantilever beams indicated an increasing tensile stress gradient. Results of microwave characterization demonstrated higher switch isolation (off-resistance) for shorter beam switches at the expense of higher insertion loss (on-resistance) and actuation voltage. A discussion of the observed released microswitch structure within the context of the measured film stresses and electrical performance will be presented.

A comparison of pad metallization in miniaturized microfabricated silicon microcantilever-based wafer probes for low contact force low skate on-wafer measurements

2021 ◽  
Author(s):  
Khadim Daffe ◽  
Jaouad Marzouk ◽  
Christophe Boyaval ◽  
Gilles Dambrine ◽  
Kamel Hadaddi ◽  
...  
Keyword(s):  
Thin Film ◽  
Contact Resistance ◽  
Contact Force ◽  
Microelectromechanical Systems ◽  
Metal Contacts ◽  
Micro Hardness ◽  
Gold Contact ◽  
Metal Metal ◽  
Silicon Cantilever ◽  
Minimal Damage

Abstract Miniaturized, microfabricated microelectromechanical systems (MEMS)-based wafer probes are used here to evaluate different contact pad metallization at low tip forces (<mN) and low skate on the on-wafer pads. The target application is low force RF probes for on-wafer measurements which cause minimal damage to both probes and pads. Low force enables the use of softer, more conductive metallisation. We have studied four different thin film contact pad metals based on their thin film electrical resistivity and micro-hardness: gold, nickel, molybdenum, and chromium. The contact pads sizes were micrometre (1.9×1.9 µm2) and sub-micrometre (0.6×0.6 µm2). The contact resistance of Au-Au, Ni-Au, Mo-Au, and Cr-Au was measured as a function of tip deflection. The tip force (loading) of the contacts was evaluated from the deflection of the cantilever. It was observed that an overtravel of 300 nm resulting in a contact force of ~400 µN was sufficient to achieve a contact resistance <1 Ω for a sub-micrometre gold contact pad. Our results are compared with an analytical model of contact resistance in loaded metal-metal contacts—a reasonable fit was found. A larger contact resistance was observed for the other metals—but their hardness may be advantageous when probing other materials. Using a combination of a rigid silicon cantilever (>1000 Nm-1) and small contact pads enabled us to show that it is the length of the pad (in contact with the surface) which determines the contact resistivity rather than the total contact pad area.

scholarly journals Back-end-of-the-line MEMS switches for power management, ESD and security

2018 ◽  
Author(s):  
Nusrat Tazin ◽  
Daniel G. Saab ◽  
Massood Tabib-Azar
Keyword(s):  
Low Temperature ◽  
Contact Resistance ◽  
Power Management ◽  
Electrostatic Discharge ◽  
Security Assessment ◽  
Device Structure ◽  
Mems Switches ◽  
Mems Switch ◽  
Turn On ◽  
Spark Gap

This paper discusses a MEMS switch that can be fabricated using low temperature (&lt;100oC) deposition and patterning techniques suitable for the back-end-of-the-line integration with CMOS. The resulting cross-bar switches can be used for electrostatic discharge protection, FPGA implementation, chip security assessment and lock-down, and circuit block power management. We discuss platinum and iron switch with turn-on voltages of ~ 1.8 V. In the case of the iron switches, we also show that they can be magnetized to have &ldquo;memory&rdquo; and stay on when turned on. Platinum switch cycling of up to 1000 times did not show any changes in their turn-on voltage and their contact resistance was unchanged. The 10-100 nm switch airgaps were formed using low temperature sputtered sacrificial polysilicon and XeF2 etching. XeF2 does not attack any of the metals used in CMOS enabling fabrication of cross-bar switches with any of these metals. Once activated, it takes ∿ 6 &nbsp;to mechanically turn on the switch that can be decreased to ~1 ns by optimizing the device structure. Interestingly, the nm-scale gaps can be used as spark gap as a fast plasma switch to discharge first followed by the activation of the MEMS switch.

Application of RF MEMS Switch for Reconfiguring Micromachined Antennas

2014 ◽  
Vol 704 ◽  
pp. 293-298
Author(s):  
Jija Rajmohan ◽  
M.R. Baiju
Keyword(s):  
Rf Mems ◽  
Low Voltage ◽  
Actuation Voltage ◽  
Rf Mems Switch ◽  
Capacitive Switch ◽  
Mems Switches ◽  
Wireless Applications ◽  
Mems Switch ◽  
Rf Components ◽  
Rf Mems Switches

For mobile and wireless applications where the size of the system has to be minimized, antenna and RF components are to be integrated on to the same substrate. The contradicting requirements of the substrate with respect to the antenna and the RF circuit can be resolved by using micromachined antennas. If the principle of reconfigurability is applied to the micromachined antenna, it increases the versatality of the system. This paper proposes reconfigurability of micromachined antennas using RF MEMS switches. In the case of micromachined antennas, which involve low voltage signals, RF MEMS switches with low actuation voltage are required for achieving reconfigurability. In this paper an RF MEMS capacitive switch operating at a low actuation voltage of 1 Volt is presented

Flexible Circuit-Based RF MEMS Switches

2001 ◽  
Author(s):  
Chunjun Wang ◽  
Ramesh Ramadoss ◽  
Simone Lee ◽  
K. C. Gupta ◽  
Victor M. Bright ◽  
...  
Keyword(s):  
Printed Circuit Board ◽  
Microelectromechanical Systems ◽  
Rf Mems ◽  
Low Cost ◽  
Polyimide Film ◽  
Circuit Board ◽  
Large Area ◽  
Mems Switches ◽  
Mems Switch ◽  
Rf Mems Switches

Abstract This paper describes a new microelectromechanical systems (MEMS) switch fabricated using flexible circuit technologies. Hundreds of such switches can be laminated onto a large-area printed circuit board (PCB) with other RF devices and circuits. The switches are fabricated using low-cost, low-loss flexible circuit material Kapton-E polyimide film. Switches with actuation voltages as low as 73 V are reported.

scholarly journals Novel Test Fixture for Characterizing MEMS Switch Microcontact Reliability and Performance

Sensors ◽  
2019 ◽  
Vol 19 (3) ◽  
pp. 579 ◽  
Author(s):  
Protap Mahanta ◽  
Farhana Anwar ◽  
Ronald Coutu
Keyword(s):  
Microelectromechanical Systems ◽  
Electrical Contact ◽  
Mems Devices ◽  
Closing Time ◽  
Test Fixture ◽  
Mems Switches ◽  
Mems Switch ◽  
Wide Range ◽  
And Performance ◽  
Hot Switching

In microelectromechanical systems (MEMS) switches, the microcontact is crucial in determining reliability and performance. In the past, actual MEMS devices and atomic force microscopes (AFM)/scanning probe microscopes (SPM)/nanoindentation-based test fixtures have been used to collect relevant microcontact data. In this work, we designed a unique microcontact support structure for improved post-mortem analysis. The effects of contact closure timing on various switching conditions (e.g., cold-switching and hot-switching) was investigated with respect to the test signal. Mechanical contact closing time was found to be approximately 1 us for the contact force ranging from 10–900 μN. On the other hand, for the 1 V and 10 mA circuit condition, electrical contact closing time was about 0.2 ms. The test fixture will be used to characterize contact resistance and force performance and reliability associated with wide range of contact materials and geometries that will facilitate reliable, robust microswitch designs for future direct current (DC) and radio frequency (RF) applications.

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