Query: Electro-thermal and mechanical analysis of a MEMS switch

Candidate papers:

abstract: Micro electro mechanical systems (MEMS) have experienced an explosive growth over the past few years driven mainly by its physical properties and its promising technological applications in many different fields, particularly in space and Radio Frequency (RF) systems. MEMS technology exhibits greater advantages over the existing semiconductor switches. In this paper, electro thermal performances of a two hot arms actuator MEMS switch have been investigated. The switch is designed using CST Microwave Studio. Some mathematical equations have been developed to see the temperature distribution of the hot arms as voltage applied on it. Based on this thermal distribution, the linear thermal expansion of the hot arms and the air gap used in this switch is expressed mathematically. The developed equations have been solved and analyzed using the MATLAB software. This analysis shows that this MEMS switch has a wider range of linear operation and has extremely higher breakdown voltage.
author_names: M Asaduzzaman

Soren Peik

Mohammed Shoaib
title: Electro thermal and mechanical analysis of a MEMS switch
venue: International Conference on Electrical Computer Engineering (ICECE 2010)
year: 2010

abstract: The micromachining technology that emerged in the late 1980s can provide micron sized sensors and actuators. These micro transducers are able to be integrated with signal conditioning and processing circuitry to form micro electromechanical systems (MEMS) that can perform real time distributed control. This capability opens up a new territory for flow control research. On the other hand, surface effects dominate the fluid flowing through these miniature mechanical devices because of the large surface to volume ratio in micron scale configurations. We need to reexamine the surface forces in the momentum equation. Owing to their smallness, gas flows experience large Knudsen numbers, and therefore boundary conditions need to be modified. Besides being an enabling technology, MEMS also provide many challenges for fundamental flow science research.
author_names: Chih-Ming Ho

Yu-Chong Tai
title: MICRO ELECTRO MECHANICAL SYSTEMS (MEMS) AND FLUID FLOWS
year: 1998

abstract: This paper deals with a relatively new area of radio frequency (RF) technology based on microelectro mechanical systems (MEMS) RF MEMS provides a class of new devices and components which display superior high frequency performance relative to conventional (usually semiconductor) devices, and which enable new system capabilities. In addition, MEMS devices are designed and fabricated by techniques similar to those of very large scale integration, and can be manufactured by traditional batch processing methods. In this paper, the only device addressed is the electrostatic microswitch perhaps the paradigm RF MEMS device. Through its superior performance characteristics, the microswitch is being developed in a number of existing circuits and systems, including radio front ends, capacitor banks, and time delay networks. The superior performance combined with ultra low power dissipation and large scale integration should enable new system functionality as well. Two possibilities addressed here are quasi optical beam steering and electrically reconfigurable antennas.
author_names: Elliott R Brown
title: RF MEMS switches for reconfigurable integrated circuits
year: 1998

abstract: Electrostatically actuated microswitches and relays have been developed at Northeastern University and Analog Devices, Inc. Here, we report a steady state thermal electrical finite element model of microswitches with gold gold contacts. The modeling results show that in a microswitch with a typical geometry, the thermal constriction occurs in the thin film trace leading up to the contact, and not at the contact interface. The model correctly predicts the switch voltage at which the drain trace melts, but underestimates the switch resistance, and therefore overestimates the failure current. SEM images indicate that the contact area increases significantly with current.
author_names: X T Yan

Nicol E McGruer

G G Adams

Sumit Majumder
title: Finite element analysis of the thermal characteristics of MEMS switches
venue: TRANSDUCERS '03. 12th International Conference on Solid State Sensors, Actuators and Microsystems. Digest of Technical Papers (Cat. No.03TH8664)
year: 2003

abstract: This paper presents a detailed steady state thermal analysis of RF MEMS capacitive switches. In the up state position, the maximum temperature on the bridge occurs at the center and is only 50/spl deg/ and 70/spl deg/C for 1 /spl mu/m thick gold and aluminum membranes, respectively, for a power dissipation in the bridge of 20 mW. This corresponds to an incident RF power of 10 W for C/sub u/ 100 fF at 12 GHz (or C/sub u/ 35 fF at 35 GHz) and R/sub s/ 0.5 /spl Omega/ In the down state position, it is shown that the bridge temperature does not increase considerably for an incident power of 1 W, and therefore, does not contribute to the reliability problems at high RF powers. On the other hand, it is our opinion that the RF current density on the leading edge of the bridge membrane is the main factor of the failure of MEMS capacitive switches at high RF powers. Two dimensional temperature measurements are currently being done at Rockwell Scientific, and will be presented at the conference.
author_names: J B Rizk

E Chaiban

Gabriel M Rebeiz
title: Steady state thermal analysis and high power reliability considerations of RF MEMS capacitive switches
venue: 2002 IEEE MTT S International Microwave Symposium Digest (Cat. No.02CH37278)
year: 2002

abstract: From the Publisher: Practical and theoretical coverage of RF MEMS for circuits and devices New RF and microwave frequency MEMS (microeletromechanical systems) have potentially enormous and widespread applications in the telecommunications industry. Components based on this technologysuch as switches, varactors, and phase shiftersexhibit virtually no power consumption or loss, making them ideally suited for use in modern telecommunications and wireless devices. This book sets out the basics of RF MEMS and describes how to design practical devices and circuits. As well as covering fundamentals, Gabriel Rebeiz offers expert tips for designers and presents a range of real world applications. Throughout, the author utilizes actual engineering examples to illustrate basic principles in theory and practice. Detailed discussion of cutting edge fabrication and packaging techniques is provided. Suitable as a tutorial for electrical and computer engineering students, or as an up to date reference for practicing circuit designers, RF MEMS provides the most comprehensive available survey of this new and important technology. Author Biography: Gabriel M. Rebeiz received his PhD from the California Institute of Technology, and is Professor of Electrical and Computer Engineering at the University of Michigan, Ann Arbor. In 1991 he was the recipient of the National Science Foundation Presidential Young Investigator Award, and in 2000 was the corecipient of the IEEE Microwave Prize. A Fellow of the IEEE and a consultant to Rockwell, Samsung, Intel, Standard MEMS, and Agilent, he has published extensively in the field of microwave technology and in the area of RF MEMS.
author_names: Gabriel M Rebeiz
title: RF MEMS: Theory, Design and Technology
year: 2003

abstract: This paper reports two unique mechanisms using "V shape" electro thermal actuators to realize large displacement and reliable contact in MEMS switches. The first mechanism is a novel displacement amplification system that enables a large in plane traveling distance for closing the gap between switch contacts. The structure features a movable end and pivot joints connecting to the amplification beam that can result in smaller actuating force distinguishing this mechanism from others. The second mechanism involves a unique latching system to provide a large lateral force for reliable contact. In both mechanisms, out of plane displacements are minimized due to the structural symmetry of the "V shape" actuators. The devices are fabricated using PolyMUMPS process. At 1 V driving voltage for 2 pairs of 3 arm V shape actuators, the displacement amplification system provides a gain of ~6.5 while consuming 2x3.8 mW power. Each 4 arm V shape latching actuator generates ~2.7 um displacement and ~240 uN contact force with a power consumption of ~2.2 mW.
author_names: Jay J Khazaai

M Haris

Hongwei Qu

James Melvin Slicker
title: Displacment amplification and latching mechanism using V shape actuators in design of electro thermal MEMS switches
venue: 2010 IEEE Sensors
year: 2010

abstract: MEMS are rapidly emerging as critical components in the telecommunications industry. This enabling technology is currently being implemented in a variety of product and engineering applications. MEMS are currently being used as optical switches to reroute light, tunable filters, and mechanical resonators. Radio frequency (RF) MEMS must be compatible with current Gallium Arsenide (GaAs) microwave integrated circuit (MMIC) processing technologies for maximum integration levels. The RF MEMS switch discussed in this paper was fabricated using various layers of polyimide, silicon oxynitride (SiON) gold, and aluminum monolithically fabricated on a GaAs substrate. Fig. 1 shows a metal contacting series switch. This switch consists of gold signal lines (transmission lines) and contact metallization. SiON was deposited to form the fixed fixed beam, and aluminum was deposited to form the top actuation electrode. To ensure product performance and reliability, RF MEMS switches are tested at both the wafer and package levels. Various processing irregularities may pass the visual inspection but fail electrical testing. This paper will focus on the failure mechanisms found in the first generation of RF MEMS developed at Sandia National Laboratories. Various tools and techniques such as scanning electron microscopy (SEM) resistive contrast imaging (RCI) focused ion beam (FIB) and thermally induced voltage alteration (TIVA) have been employed to diagnose the failure mechanisms. The analysis performed using these tools and techniques led to corrective actions implemented in the next generation of RF MEMS metal contacting series switches.
author_names: Jeremy A Walraven

Edward I Cole

Lynn R Sloan

Susan L Hietala

C P Tigges

Christopher W Dyck
title: Failure analysis of radio frequency (rf) micro electro mechanical systems (MEMS)
venue: SPIE MOEMS MEMS
year: 2001

abstract: Self heating in electrostatically actuated RF MEM capacitive shunt switches is analyzed by coupled electrical and thermal simulations using three dimensional finite element analysis. The result shows that despite highly nonuniform current and temperature distributions, the self heating effect can be approximated by lumped thermal resistances of the switch membrane and the substrate. Additionally, since the thermal resistance of thermally insulating substrates such as quartz is significant compared to that of the membrane, it is important to consider the heat transfer across both the membrane and the substrate.
author_names: F Solazzi

Cristiano Palego

Subrata Halder

James C M Hwang

Alessandro Faes

Viviana Mulloni

Benno Margesin

P Farinelli

Roberto Sorrentino
title: Electro thermal analysis of RF MEM capacitive switches for high power applications
venue: 2010 Proceedings of the European Solid State Device Research Conference
year: 2010

abstract: Micro electro mechanical sensor systems (MEMS Sensors) are being considered for a variety of applications in space and launch operations. These applications include health and status monitoring, environmental monitoring, automated control, repair and service. A microaccelerometer performance was characterized in detail and their failure mechanisms were identified by subjecting them to 1,000 thermal cycles under extreme temperatures 65 to +150degC) and to 30,000 shocks at 2,000 g. In addition, several other MEMS sensors (microaccelerometers and temperature sensors) were characterized at the extremes of their temperature ranges. It consists of a 10 day test that subjected various microaccelerometers to both continuous thermal cycling between temperatures of 40 degC and +85 degC and mechanical loading. A comparison of the data from microaccelerometers of the same type and between several types will be presented. Self test output signals and X ray evaluation test data after completion of 182 thermal cycles will also be presented.
author_names: Reza Ghaffarian

David G Sutton

Paul D Chaffee

N Marquez
title: Thermal and Mechanical Reliability of Five COTS MEMS Accelerometers
year: 2002