Microelectromechanical Systems Cantilever Resonators: Pressure-Dependent Gas Film Damping

2020 ◽  
Vol 142 (9) ◽  
Author(s):  
Chu Rainer Kwang-Hua
Keyword(s):  
Quality Factor ◽  
Knudsen Number ◽  
Microelectromechanical Systems ◽  
Unit Length ◽  
Mems Devices ◽  
Dynamical Friction ◽  
Quality Factors ◽  
Wafer Level ◽  
Unsteady Fluid ◽  
Parameter Per Unit Length

Abstract Under near-vacuum conditions, the fluid frictional dissipation or approximately the inverse of the quality factor of a microcantilever once the intrinsic dissipation can be neglected is proportional to the low pressure. We shall investigate the dynamic behavior of micro-electromechanical systems (MEMS) devices via the calculation of the quality factor or frictional damping forces resulting from surrounding gases. Here, we illustrated some specific examples relevant to the computation of the quality factor or dynamical friction for an oscillating microcantilever in air via measurements of the paper of Okada et al. (Okada, H., Itoh, T., and Suga, T., 2008, Wafer Level Sealing Characterization Method Using Si Micro Cantilevers,” Sens. Actuators A, 147(2), pp. 359–364) considering the quality factors of the CM (a label for a microcantilever: 500 × 90 × 5 μm3 Si microcantilever (the measured resonance frequency: 23.7 kHz) and the paper of Kara et al. (Kara, V., Yakhot, V., and Ekinci, K. L., 2017, Generalized Knudsen Number for Unsteady Fluid Flow, Phys. Rev. Lett., 118(7), p. 074505) in rarefied gases regime. We present the corrected quality factor or dynamical friction over the whole range of the Knudsen number considering the CM part by Okada et al. Our new plot considering the quality factor which is proportional to the inverse of the dissipative friction parameter per unit length, pressure as well as the Knudsen number over the whole range should be useful to researchers in this field.

Microsensors, MEMS and NEMS Based Complex Adaptive Smart Devices and Systems

2001 ◽  
Author(s):  
Vijay K. Varadan
Keyword(s):  
Self Assembly ◽  
Communication Systems ◽  
Microelectromechanical Systems ◽  
System Level ◽  
Smart Devices ◽  
Mems Devices ◽  
Wafer Level ◽  
Sensors And Actuators ◽  
Complex Adaptive ◽  
Microelectronics Industry

Abstract The microelectronics industry has seen explosive growth during the last thirty years. Extremely large markets for logic and memory devices have driven the development of new materials, and technologies for the fabrication of even more complex devices with features sizes now down at the sub micron level. Recent interest has arisen in employing these materials, tools and technologies for the fabrication of miniature sensors and actuators and their integration with electronic circuits to produce smart devices and MicroElectroMechanical Systems (MEMS). This effort offers the promise of: 1. Increasing the performance and manufacturability of both sensors and actuators by exploiting new batch fabrication processes developed for the IC and microelectronics industry. Examples include micro stereo lithographic and micro molding techniques. 2. Developing novel classes of materials and mechanical structures not possible previously, such as diamond like carbon, silicon carbide and carbon nanotubes, micro-turbines and micro-engines. 3. Development of technologies for the system level and wafer level integration of micro components at the nanometer precision, such as self-assembly techniques and robotic manipulation. 4. Development of control and communication systems for MEMS devices, such as optical and RF wireless, and power delivery systems.

Wafer-Level Strength and Fracture Toughness Testing of Surface-Micromachined MEMS Devices

1999 ◽  
Vol 605 ◽  
Author(s):  
H. Kahn ◽  
N. Tayebi ◽  
R. Ballarini ◽  
R.L. Mullen ◽  
A.H. Heuer
Keyword(s):  
Fracture Toughness ◽  
Tensile Strength ◽  
Microelectromechanical Systems ◽  
Reliability Prediction ◽  
Bend Strength ◽  
Mems Devices ◽  
Wafer Level ◽  
Toughness Testing ◽  
Loading Devices

AbstractDetermination of the mechanical properties of MEMS (microelectromechanical systems) materials is necessary for accurate device design and reliability prediction. This is most unambiguously performed using MEMS-fabricated test specimens and MEMS loading devices. We describe here a wafer-level technique for measuring the bend strength, fracture toughness, and tensile strength of MEMS materials. The bend strengths of surface-micromachined polysilicon, amorphous silicon, and polycrystalline 3C SiC are 5.1±1.0, 10.1±2.0, and 9.0±1.0 GPa, respectively. The fracture toughness of undoped and P-doped polysilicon is 1.2±0.2 MPa√m, and the tensile strength of polycrystalline 3C SiC is 3.2±1.2 GPa. These results include the first report of the mechanical strength of micromachined polycrystalline 3C SiC.

RF MEMS Switch Heat Dissipation in Discrete and Wafer-Level MEMS Packages

2002 ◽  
Author(s):  
Lei L. Mercado ◽  
Tien-Yu Tom Lee ◽  
Shun-Meen Kuo ◽  
Vern Hause ◽  
Craig Amrine
Keyword(s):  
Power Density ◽  
Contact Area ◽  
Heat Dissipation ◽  
Microelectromechanical Systems ◽  
Rf Mems ◽  
Material Selection ◽  
Junction Temperature ◽  
Mems Devices ◽  
Wafer Level ◽  
Die Attach

In discrete RF (Radio Frequency) MEMS (MicroElectroMechanical Systems) packages, MEMS devices were fabricated on Silicon or GaAs (Galium Arsenide) chips. The chips were then attached to substrates with die attach materials. In wafer-level MEMS packages, the switches were manufactured directly on substrates. For both types of packages, when the switches close, a contact resistance of approximately 1 Ohm exists at the contact area. As a result, during switch operations, a considerable amount of heat is generated in the minuscule contact area. The power density at the contact area could be up to 1000 times higher than that of typical power amplifiers. The high power density may overheat the contact area, therefore affect switch performance and jeopardize long-term switch reliabilities. In this paper, thermal analysis was performed to study the heat dissipation at the switch contact area. The goal is to control the “hot spots” and lower the maximum junction temperature at the contact area. A variety of chip materials, including Silicon, GaAs have been evaluated for the discrete packages. For each chip material, the effect of die attach materials was considered. For the wafer-level packages, various substrate materials, such as ceramic, glass, and LTCC (Low-Temperature Cofire Ceramic) were studied. Thermal experiments were conducted to measure the temperature at the contact area and its vicinity as a function of DC and RF powers. Several solutions in material selection and package configurations were explored to enable the use of MEMS with chips or substrates with relatively poor thermal conductivity.

Performance Modification of SiC MEMS

2009 ◽  
Vol 615-617 ◽  
pp. 621-624 ◽  
Author(s):  
Florentina Niebelschütz ◽  
Klemens Brueckner ◽  
Volker Cimalla ◽  
Matthias A. Hein ◽  
Jörg Pezoldt
Keyword(s):  
Residual Stress ◽  
Resonant Frequency ◽  
Epitaxial Growth ◽  
Quality Factor ◽  
Growth Conditions ◽  
Mems Devices ◽  
Quality Factors ◽  
Resonant Frequencies ◽  
Raman Analysis

The adjustment of the properties of 3C-SiC based MEMS devices, i.e. the quality factor and resonant frequency, was achieved by changing the residual stress and the 3C-SiC material quality of the SiC-layers grown on Si(111) by manipulating the nucleation conditions and growth conditions with Ge deposition prior to the carbonization and epitaxial growth. Previous Raman analysis of the SiC-layers and measured resonant frequencies and quality factors of the processed MEMS show a dependence on the Ge amount at the interface of the Si/SiC heterostructure, which allows to adjust the MEMS properties to the requirements needed for certain applications.

Packaging Options for MEMS Devices

MRS Bulletin ◽  
2003 ◽  
Vol 28 (1) ◽  
pp. 51-54 ◽  
Author(s):  
Erik Jung
Keyword(s):  
Integrated Circuit ◽  
Microelectromechanical Systems ◽  
Mems Devices ◽  
Single Chip ◽  
Wafer Level ◽  
Product Failure ◽  
Product Success ◽  
Microelectronics Industry ◽  
The Right ◽  
Crucial Part

AbstractMicroelectromechanical systems (MEMS) devices can be delicate structures sensitive to damage from handling or environmental influences. Their functionality may furthermore depend on sealing out the environment or being in direct contact with it. Stress, thermal load, and contaminants may change their characteristics. Here, packaging technology is challenged to extend from microelectronics toward MEMS and optoelectronic MEMS (MOEMS). Today's approaches rely on modified single-chip packages derived from the microelectronics industry, wafer-level capping to enable the device to be packaged like an integrated circuit, or highly specialized packages designed to complement the function of the MEMS device itself. Selecting the proper packaging method may tip the scale toward a product success or a product failure. Choosing the right technology, therefore, is a crucial part of the product design.

A System for Electromechanical Reliability Testing of MEMS Devices

2006 ◽  
Author(s):  
Stefan Spinner ◽  
Michael Doelle ◽  
Patrick Ruther ◽  
Oliver Paul ◽  
Ilia Polian ◽  
...  
Keyword(s):  
Mechanical Stress ◽  
Microelectromechanical Systems ◽  
Automated Analysis ◽  
Dynamic Loads ◽  
Reliability Testing ◽  
Mems Devices ◽  
Single Chip ◽  
Wafer Level ◽  
Optical Inspection

Abstract This paper reports on a setup and a method that enables automated analysis of mechanical stress impact on microelectromechanical systems (MEMS). In this setup both electrical and optical inspection are available. Reliability testing is possible on a single chip as well as on the wafer level. Mechanical stress is applied to the tested structure with programmable static forces up to 3.6 N and dynamic loads at frequencies up to 20 Hz. The applications of the presented system include the postmanufacturing test, characterization and stress screens as well as reliability studies. We report preliminary results of long-term reliability testing obtained for a CMOS-based stress sensor.

MEMS Bandpass Filters Based on Cyclic Coupling Architectures

2009 ◽  
Author(s):  
Venkata Bharadwaj Chivukula ◽  
Jeffrey F. Rhoads
Keyword(s):  
Quality Factor ◽  
Integrated Circuit ◽  
Microelectromechanical Systems ◽  
Performance Metrics ◽  
Bandpass Filters ◽  
Superior Performance ◽  
Quality Factors ◽  
Open Chain ◽  
Closed Chain ◽  
Parameter Ranges

Resonant microelectromechanical systems (MEMS) offer distinct utility in signal processing and wireless communications applications due to their comparatively-high quality factors, low power consumption, and ease of integration with existing integrated circuit (IC) technologies. While a number of efforts have previously demonstrated the use of mechanically-coupled microresonators in bandpass signal filtering applications, the vast majority of these works have emphasized the use of resonator chains coupled in an open configuration, wherein the terminating (end) elements in the array are coupled to only a single resonator and the interior resonators are coupled solely to their nearest neighbors. While this configuration suffices for many MEMS-based filter designs, it is not guaranteed to be an optimal coupling architecture. The present work explores an alternative class of MEMS bandpass filters based on cyclically-coupled, closed-chain resonator configurations and specifically examines the pertinent performance metrics (effective quality factor, shape factor, bandwidth, ripple, and maximum transmission) associated with each architecture. By varying coupling strength and the quality factor of individual resonators over wide, yet realistic, parameter ranges, regions of superior performance for both open- and closed-chain filter architectures have been observed. Of particular interest here, is the fact that preliminary results indicate that cyclically-coupled resonator configurations exhibit improved ripple metrics, reduced frequency dependence within the passband, and, generally speaking, more robustness to process-induced variations than their open-chain counterparts. As such, cyclically-coupled filter designs, with further refinement, may ultimately lead to an improved MEMS bandpass filter capability.

Mechanics of Direct Wafer Bonding

2003 ◽  
Author(s):  
K. T. Turner ◽  
S. M. Spearing
Keyword(s):  
Wafer Bonding ◽  
Microelectromechanical Systems ◽  
Surface Condition ◽  
Bonding Process ◽  
Mems Devices ◽  
Wafer Level ◽  
Modeling Framework ◽  
Etch Patterns ◽  
Direct Wafer Bonding ◽  
Bonding Failure

Direct wafer bonding, also known as fusion bonding, has emerged as a key process in the manufacture of microelectromechanical systems (MEMS). The use of wafer bonding increases design flexibility, allows integration of dissimilar materials, and permits wafer-level packaging. While direct wafer bonding processes are becoming more prevalent in the fabrication of MEMS devices, failure during the bonding process is often a problem and is not completely understood. A modeling framework, based on the mechanics of the bonding process, has been on the mechanics of the bonding process, has been developed to correlate bonding failure to wafer geometry, surface condition, and etch patterns. The modeling approach is based on an energy balance between the reduction in surface energy as the bond is formed and the strain energy that is stored in the wafers as they conform to each other. The model allows the effect of flatness deviations, wafer geometry (i.e. thickness, diameter), wafer mounting, and etched features on the bonding process to be shown. Modeling results demonstrate that wafer bow, wafer thickness, and certain types of etch patterns are critical factors in controlling bonding success. Bonding experiments, in which specific flatness deviations and etch patterns have been introduced on wafers prior to bonding, have been carried out and compared to the modeling results. The understanding of the process gained through the modeling can be used to set tolerances on wafers, assist in mask layout, and guide the design of bonding equipment to ensure success in direct wafer bonding processes.

scholarly journals Measurement of Electrical Properties of Superconducting YBCO Thin Films in the VHF Range

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3360
Author(s):  
Yakir Dahan ◽  
Eldad Holdengreber ◽  
Elichai Glassner ◽  
Oz Sorkin ◽  
Shmuel E. Schacham ◽  
...  
Keyword(s):  
Thin Films ◽  
Theoretical Model ◽  
Quality Factor ◽  
High Frequency ◽  
Unit Length ◽  
Superconducting Thin Films ◽  
Electrical Parameters ◽  
Very High Frequency ◽  
Production Constraints ◽  
Very High

A new measurement technique of electrical parameters of superconducting thin films at the Very High Frequency (VHF) range is described, based on resonators with microstrip (MS) structures. The design of an optimal resonator was achieved, based on a thorough theoretical analysis, which is required for derivation of the exact configuration of the MS. A theoretical model is presented, from which an expression for the attenuation of a MS line can be derived. Accordingly, simulations were performed, and an optimal resonator for the VHF range was designed and implemented. Production constraints of YBa2Cu3O7 (YBCO) limited the diameter of the sapphire substrate to 3″. Therefore, a meander configuration was formed to fit the long λ/4 MS line on the wafer. By measuring the complex input reflection coefficients of a λ/4 resonator, we extracted the quality factor, which is mainly affected by the dielectric and conductor attenuations. The experimental results are well fitted by the theoretical model. The dielectric attenuation was calculated using the quasi-static analysis of the MS line. An identical copper resonator was produced and measured to compare the properties of the YBCO resonator in reference to the copper one. A quality factor of ~6·105 was calculated for the YBCO resonator, three orders of magnitude larger than that of the copper resonator. The attenuation per unit length of the YBCO layer was smaller by more than five orders of magnitude than that of the copper.

An all-silicon process platfom for wafer-level vacuum packaged MEMS devices

2021 ◽  
pp. 1-1
Author(s):  
Mustafa Mert Torunbalci ◽  
Hasan Dogan Gavcar ◽  
Ferhat Yesil ◽  
Said Emre Alper ◽  
Tayfun Akin
Keyword(s):  
Mems Devices ◽  
Wafer Level
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