Laser Repair Process Yields for MEMS Devices Adhered During Release or Operation

2003 ◽  
Author(s):  
Sai B. Koppaka ◽  
Leslie M. Phinney
Keyword(s):  
Isopropyl Alcohol ◽  
Failure Modes ◽  
Microelectromechanical Systems ◽  
Repair Process ◽  
Mems Devices ◽  
Thermomechanical Model ◽  
Chemical Treatments ◽  
Model Predictions ◽  
Supercritical Co2 Drying ◽  
Better Than

Undesirable adhesion in microelectromechanical systems (MEMS) is referred to as stiction and is a principal failure mechanism in surface-micromachined MEMS devices. Adhesive failures can occur in a number of ways. The adhesive failures that occur during the release stage, which includes the etching of sacrificial layers, the subsequent chemical treatments, and the drying processes, are referred to as release-related stiction and failures that occur while the device is in operation are referred to as in-use stiction. A method of repairing these stiction-failed structures released from isopropyl alcohol (IPA) by Nd:YAG laser irradiation is described by Rogers et al. [1]. The current paper reports the effectiveness of the laser repair process and the corresponding thermomechanical model predictions for microcantilevers that have failed due to release from water, octadecyltrichlorosilane (OTS) and supercritical CO2 drying, along with IPA released structures. The paper also discusses the efficiency of the model and the laser repair process for devices that have failed due to in-use stiction. The results show that the laser repair process is very effective for both failure modes and that the model predicts the laser repair of cantilevers that have failed due to release-related stiction much better than for in-use stiction failed cantilevers.

scholarly journals A Review on Key Issues and Challenges in Devices Level MEMS Testing

2016 ◽  
Vol 2016 ◽  
pp. 1-14 ◽  
Author(s):  
Muhammad Shoaib ◽  
Nor Hisham Hamid ◽  
Aamir Farooq Malik ◽  
Noohul Basheer Zain Ali ◽  
Mohammad Tariq Jan
Keyword(s):  
Failure Modes ◽  
Microelectromechanical Systems ◽  
Operating Conditions ◽  
Mems Devices ◽  
Test Technique ◽  
Parallel Testing ◽  
Test Systems ◽  
Key Issues ◽  
Mems Testing ◽  
The Cost

The present review provides information relevant to issues and challenges in MEMS testing techniques that are implemented to analyze the microelectromechanical systems (MEMS) behavior for specific application and operating conditions. MEMS devices are more complex and extremely diverse due to the immersion of multidomains. Their failure modes are distinctive under different circumstances. Therefore, testing of these systems at device level as well as at mass production level, that is, parallel testing, is becoming very challenging as compared to the IC test, because MEMS respond to electrical, physical, chemical, and optical stimuli. Currently, test systems developed for MEMS devices have to be customized due to their nondeterministic behavior and complexity. The accurate measurement of test systems for MEMS is difficult to quantify in the production phase. The complexity of the device to be tested required maturity in the test technique which increases the cost of test development; this practice is directly imposed on the device cost. This factor causes a delay in time-to-market.

scholarly journals The duration-energy-size enigma for acoustic emission

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Blai Casals ◽  
Karin A. Dahmen ◽  
Boyuan Gou ◽  
Spencer Rooke ◽  
Ekhard K. H. Salje
Keyword(s):  
Acoustic Emission ◽  
Mean Field Theory ◽  
Mean Field ◽  
Maximum Amplitude ◽  
Time Profile ◽  
Power Law Distribution ◽  
Model Predictions ◽  
Ae Signal ◽  
Strain Signal ◽  
Better Than

AbstractAcoustic emission (AE) measurements of avalanches in different systems, such as domain movements in ferroics or the collapse of voids in porous materials, cannot be compared with model predictions without a detailed analysis of the AE process. In particular, most AE experiments scale the avalanche energy E, maximum amplitude Amax and duration D as E ~ Amaxx and Amax ~ Dχ with x = 2 and a poorly defined power law distribution for the duration. In contrast, simple mean field theory (MFT) predicts that x = 3 and χ = 2. The disagreement is due to details of the AE measurements: the initial acoustic strain signal of an avalanche is modified by the propagation of the acoustic wave, which is then measured by the detector. We demonstrate, by simple model simulations, that typical avalanches follow the observed AE results with x = 2 and ‘half-moon’ shapes for the cross-correlation. Furthermore, the size S of an avalanche does not always scale as the square of the maximum AE avalanche amplitude Amax as predicted by MFT but scales linearly S ~ Amax. We propose that the AE rise time reflects the atomistic avalanche time profile better than the duration of the AE signal.

Stiction Failure Mechanisms of the Micromachined Electrostatic Comb-Drive Structures

2011 ◽  
Vol 80-81 ◽  
pp. 850-854
Author(s):  
Yi Shen Xu ◽  
Ji Hua Gu ◽  
Zhi Tao
Keyword(s):  
Failure Modes ◽  
Failure Mechanisms ◽  
Mems Devices ◽  
Comb Drive ◽  
Interfacial Forces ◽  
Restoring Forces ◽  
Critical Investigation

Stiction is one of the most important and almost unavoidable problems in MEMS, which usually occurs when the restoring forces of the microstructures are unable to overcome the interfacial forces. Stiction could compromise the performance and reliability of the MEMS devices or may even make them malfunction. One of the pivotal process of advancing the performance and reliability of MEMS is to comprehend the failure modes and failure mechanisms of these microdevices. This article provides a critical investigation on the stiction failure mechanisms of the micromachined electrostatic comb-drive structures, which is significant to improve the reliability of microdevices, especially for microfilters, microgrippers, microaccelerometers, microgyroscopes, microrelays, and so on.

Comparison of Probabilistic and Possibility Theory-Based Methods for Design Against Catastrophic Failure Under Uncertainty

1999 ◽  
Author(s):  
Efstratios Nikolaidis ◽  
Harley Cudney ◽  
Sophie Chen ◽  
Raphael T. Haftka ◽  
Raluca Rosca
Keyword(s):  
Probabilistic Models ◽  
Failure Modes ◽  
Possibility Theory ◽  
Probabilistic Methods ◽  
Sufficient Information ◽  
Catastrophic Failure ◽  
Design Problems ◽  
Available Information ◽  
Theoretical Foundations ◽  
Better Than

Abstract This paper compares probabilistic and possibility-based methods for design against catastrophic failure under uncertainty. It studies the effect of the amount of information on the effectiveness of each method. The study is confined to problems where the boundary between survival and failure is sharp. First, the paper examines the theoretical foundations of probability and possibility. It also compares the two methods when they are used to assess the risk of a system. Finally, it compares the two methods on two design problems. A major difference between probability and possibility is in the axioms about the union of events. Because of this difference, probability and possibility calculi are fundamentally different and one cannot simulate possibility calculus using probabilistic models. It is shown that possibility-based methods can be less conservative than probability-based methods in systems with many failure modes. On the other hand, possibility-based methods tend to be more conservative than probability-based methods in systems that fail only if many unfavorable events occur simultaneously. Probabilistic methods are better than possibility-based methods if sufficient information is available. However, the latter can be better if little information is available. A principal reason is that it is easier to identify the most conservative possibilistic model than the most conservative probabilistic model that is consistent with the available information.

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.

MEMS-Enabled Smart Beam-Steering Antennas

2014 ◽  
pp. 183-203
Author(s):  
Hadi Mirzajani ◽  
Habib Badri Ghavifekr ◽  
Esmaeil Najafi Aghdam
Keyword(s):  
Microelectromechanical Systems ◽  
Rf Mems ◽  
Beam Steering ◽  
Smart Antennas ◽  
Phase Shifters ◽  
Rapid Rate ◽  
Mems Devices ◽  
Batch Fabrication ◽  
Mems Technology ◽  
Smart Beam

In recent years, Microelectromechanical Systems (MEMS) technology has seen a rapid rate of evolution because of its great potential for advancing new products in a broad range of applications. The RF and microwave devices and components fabricated by this technology offer unsurpassed performance such as near-zero power consumption, high linearity, and cost effectiveness by batch fabrication in respect to their conventional counterparts. This chapter aims to give an in-depth overview of the most recently published methods of designing MEMS-based smart antennas. Before embarking into the different techniques of beam steering, the concept of smart antennas is introduced. Then, some fundamental concepts of MEMS technology such as micromachining technologies (bulk and surface micromachining) are briefly discussed. After that, a number of RF MEMS devices such as switches and phase shifters that have applications in beam steering antennas are introduced and their operating principals are completely explained. Finally, various configurations of MEMS-enabled beam steering antennas are discussed in detail.

Experimental study on the seismic performance of traditional timber mortise-tenon joints with different looseness under low-cyclic reversed loading

2018 ◽  
Vol 22 (6) ◽  
pp. 1312-1328 ◽  
Author(s):  
Jianyang Xue ◽  
Rui Guo ◽  
Liangjie Qi ◽  
Dan Xu
Keyword(s):  
Energy Dissipation ◽  
Seismic Performance ◽  
Failure Modes ◽  
Artificial Defect ◽  
Reversed Loading ◽  
Energy Dissipation Capacity ◽  
Strength And Stiffness ◽  
Seismic Behaviors ◽  
Damage Type ◽  
Better Than

The majority of existing ancient timber structures have different degrees of damage. The looseness of mortise-tenon joints is a kind of typical damage type. In order to study the influence of looseness on the seismic performance of mortise-tenon joints, six through-tenon joints and six dovetail-tenon joints with scale 1:3.2 were fabricated according to the requirements of the engineering fabrication method of Chinese Qing Dynasty. Each type of joints consisted of one intact joint and five artificial loose joints, and the artificial defect was made to simulate looseness by cutting the tenon sectional dimension. Based on experiments of two types of joints under low-cyclic reversed loading, the seismic behaviors of joints such as failure modes, hysteretic loops and skeleton curves, strength and stiffness degradation, and energy dissipation capacity were studied. Moreover, the comparative analyses of seismic performance between two types of joints were carried out. The variation tendency of seismic behaviors of two types of joints has similarities, and there are some differences due to their different structural styles. The results indicate that squeeze deformation between tenon and mortise of two types of joints occurred. The shape of hysteretic loops of two types of joints is reverse-Z-shape, and the pinching effect of hysteretic loops becomes more obvious with the increase in looseness, among which of through-tenon joints is more obvious than that of dovetail-tenon joints. The carrying capacity, stiffness, and energy dissipation capacity of loose joints are significantly lower than that of the intact one, and the energy dissipation capacity of dovetail-tenon joints is better than that of through-tenon joints. The rotation angles of two types of joints can reach 0.12 rad, and the loose joints still have great deformation capacity.

A Renewal Weakest-Link Model of Strength Distribution of Polycrystalline Silicon MEMS Structures

2019 ◽  
Vol 86 (8) ◽  
Author(s):  
Zhifeng Xu ◽  
Roberto Ballarini ◽  
Jia-Liang Le
Keyword(s):  
Experimental Data ◽  
Polycrystalline Silicon ◽  
Microelectromechanical Systems ◽  
Strength Distribution ◽  
Material Strength ◽  
Mems Devices ◽  
Efficient Computation ◽  
Weakest Link ◽  
Large Size ◽  
The Stability

Experimental data have made it abundantly clear that the strength of polycrystalline silicon (poly-Si) microelectromechanical systems (MEMS) structures exhibits significant variability, which arises from the random distribution of the size and shape of sidewall defects created by the manufacturing process. Test data also indicated that the strength statistics of MEMS structures depends strongly on the structure size. Understanding the size effect on the strength distribution is of paramount importance if experimental data obtained using specimens of one size are to be used with confidence to predict the strength statistics of MEMS devices of other sizes. In this paper, we present a renewal weakest-link statistical model for the failure strength of poly-Si MEMS structures. The model takes into account the detailed statistical information of randomly distributed sidewall defects, including their geometry and spacing, in addition to the local random material strength. The large-size asymptotic behavior of the model is derived based on the stability postulate. Through the comparison with the measured strength distributions of MEMS specimens of different sizes, we show that the model is capable of capturing the size dependence of strength distribution. Based on the properties of simulated random stress field and random number of sidewall defects, a simplified method is developed for efficient computation of strength distribution of MEMS structures.

scholarly journals Stability Improvement of Flexible Shallow Shells Using Neutron Radiation

Materials ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3187
Author(s):  
Anton V. Krysko ◽  
Jan Awrejcewicz ◽  
Irina V. Papkova ◽  
Vadim A. Krysko
Keyword(s):  
Temperature Field ◽  
Neutron Irradiation ◽  
Microelectromechanical Systems ◽  
Neutron Radiation ◽  
Middle Surface ◽  
Aviation Industry ◽  
Irradiation Effect ◽  
Structural Members ◽  
Mems Devices ◽  
Shallow Shells

Microelectromechanical systems (MEMS) are increasingly playing a significant role in the aviation industry and space exploration. Moreover, there is a need to study the neutron radiation effect on the MEMS structural members and the MEMS devices reliability in general. Experiments with MEMS structural members showed changes in their operation after exposure to neutron radiation. In this study, the neutron irradiation effect on the flexible MEMS resonators’ stability in the form of shallow rectangular shells is investigated. The theory of flexible rectangular shallow shells under the influence of both neutron irradiation and temperature field is developed. It consists of three components. First, the theory of flexible rectangular shallow shells under neutron radiation in temperature field was considered based on the Kirchhoff hypothesis and energetic Hamilton principle. Second, the theory of plasticity relaxation and cyclic loading were taken into account. Third, the Birger method of variable parameters was employed. The derived mathematical model was solved using both the finite difference method and the Bubnov–Galerkin method of higher approximations. It was established based on a few numeric examples that the irradiation direction of the MEMS structural members significantly affects the magnitude and shape of the plastic deformations’ distribution, as well as the forces magnitude in the shell middle surface, although qualitatively with the same deflection the diagrams of the main investigated functions were similar.

Infrared Radiative Properties of Heavily Doped Silicon at Room Temperature

2007 ◽  
Author(s):  
S. Basu ◽  
B. J. Lee ◽  
Z. M. Zhang
Keyword(s):  
Carrier Mobility ◽  
Room Temperature ◽  
Radiative Properties ◽  
Multilayer Thin Films ◽  
Mems Devices ◽  
Si Substrate ◽  
Model Predictions ◽  
Doped Silicon ◽  
Infrared Spectrometer ◽  
Heavily Doped

This paper describes an experimental investigation on the infrared radiative properties of heavily-doped silicon (Si) at room temperature. Lightly-doped Si wafers were ion implanted with boron and phosphorus atoms to doping concentrations of 1×1020 and 1×1021 cm−3. Rapid thermal annealing was performed to activate the implanted dopants. A Fourier-transform infrared spectrometer was employed to measure the normal transmittance as well as reflectance of the samples in the spectral region from 2 to 20 μm. Accurate carrier mobility and ionization models were identified after carefully reviewing the available literature, and then incorporated into Drude model to predict the dielectric function of doped Si. The radiative properties of doped Si samples were calculated by treating the doped region as multilayer thin films of different doping concentrations on a thick Si substrate. The measured spectral transmittance and reflectance agree well with the model predictions. The results obtained from this study will facilitate the future applications of heavily-doped Si in semiconductor as well as MEMS devices.

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