A physical model to predict stiction in MEMS

Spengen, W. Merlijn van; Puers, Robert; Wolf, Ingrid De

doi:10.1088/0960-1317/12/5/329

Cited by 186 publications

(105 citation statements)

References 23 publications

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“…2 [5]. The contact then becomes equivalent to a bearing area ( figure 3), where the hardness H determines the minimum area the flat contact needs to be to sustain the applied load without yielding [12].…”

Section: Differences Between Different Contacting Rough Surfaces Withmentioning

confidence: 99%

“…The details of the adhesion modeling are described in an earlier paper [5]. Capillary condensation is present for every part of the apparent contact where the distance between the surfaces is less than two times the Kelvin radius.…”

Section: Adhesion Comes Into Playmentioning

confidence: 99%

“…Several key publications have addressed the details of this surface roughness effect on adhesion, ranging from assuming (relatively) simple plastic [5] or elastic contact [6] to the introduction of a completely new contact mechanics framework such as in [7]. The objective of all these approaches is, in one way or another, to find the distribution of the distance between the contacting surfaces.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

A physical model to describe the distribution of adhesion strength in MEMS, or why one MEMS device sticks and another ‘identical’ one does not

Spengen

2015

J. Micromech. Microeng.

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In this paper a model is presented that describes the distribution of adhesion values typically experimentally observed for different MEMS devices that have been fabricated in the same way. This spread is attributed to the fact that different devices differ in the details of their surface roughness, even if these surface roughnesses are modeled as coming from the same 'parent' stochastic process.Using Monte Carlo simulations, the effect of surface roughness and relative humidity has been evaluated in detail, both on the expected mean value of the surface interaction energy between the MEMS surfaces, and the expected spread on this value from device to device.By comparing the new model to existing literature reporting this experimentally observed spread, we have found excellent agreement between the experimental spread observed, and the spread calculated with the theoretical model using Monte Carlo simulations.This work paves the way to detailed adhesion failure predictive modeling. It may be used to assess the reliability of MEMS designs that rely on contacting surfaces for their operation, but have a limited restoring force available to separate the surfaces when in contact.

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Section: Differences Between Different Contacting Rough Surfaces Withmentioning

confidence: 99%

Section: Adhesion Comes Into Playmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

A physical model to describe the distribution of adhesion strength in MEMS, or why one MEMS device sticks and another ‘identical’ one does not

Spengen

2015

J. Micromech. Microeng.

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“…Figure 1b and 1c shows the arch-shaped and S-shaped adhered microbeams, respectively. For the arch-shaped microbeam, the contact area is extremely small; therefore, the measurement largely depends on the contact local properties and the statistical error is relatively much higher [4]. de Boer et al [15] argue that a better way of studying meaningful surface interaction energy is to investigate the S-shaped case only.…”

Section: Physical Model and Problem Formulationmentioning

confidence: 99%

Vibration of an adhered microbeam under a periodically shaking electrical force

Yin¹,

Zhao

2005

Journal of Adhesion Science and Technology

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Abstract-The vibration analysis of an adhered S-shaped microbeam under alternating sinusoidal voltage is presented. The shaking force is the electrical force due to the sinusoidal voltage. During vibration, both the microbeam deflection and the adhesion length keep changing. The microbeam deflection and adhesion length are numerically determined by the iteration method. As the adhesion length keeps changing, the domain of the equation of motion for the microbeam (unadhered part) changes correspondingly, which results in changes of the structure natural frequencies. For this reason, the system can never reach a steady state. The transient behaviors of the microbeam under different shaking frequencies are compared. We deliberately choose the initial conditions to compare our dynamic results with the existing static theory. The paper also analyzes the changing behavior of adhesion length during vibration and an asymmetric pattern of adhesion length change is revealed, which may be used to guide the dynamic de-adhering process. The abnormal behavior of the adhered microbeam vibrating at almost the same frequency under two quite different shaking frequencies is also shown. The Galerkin method is used to discretize the equation of motion and its convergence study is also presented. The model is only applicable in the case that the peel number is equal to 1. Some other model limitations are also discussed.

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“…31,32 In general, the interaction between the bonding surfaces is determined by capillary forces, van der Waals forces, electrostatic forces and forces related to hydrogen and solid bridging. 31,32 It is very unlikely, however, that capillary forces play a role in vacuum bonding of recesses. In addition to the environmental conditions such as temperature, the roughness of the bonding surfaces has profound effect on the bonding process.…”

Section: Effect Of Temperature and Dilution Of Sc1 On Fusion Bonding-mentioning

confidence: 99%

Nondestructive Characterization of Fusion and Plasma Activated Wafer Bonding Using Mesa and Recess Structures

Varpula

Suni

Dekker

2014

ECS J. Solid State Sci. Technol.

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We present two methods for characterization of wafer bonding. They are based on recess and mesa bond test structures with various shapes, measurement of unbonded regions using scanning acoustic microscopy (SAM), and image analysis. The first method maps locally the surface energy across the bonded wafers using the measured deformations around these structures and the finite element method (FEM). The FEM analysis is supported by analytical modeling. The second method uses the measured bonding probabilities of 10-19 nm deep recess bond test structures in investigation of surface interactions and in determination of the average of the surface energy at the wafer level. The present methods and proposed optimized test structures allow the evaluation of surface cleans without destructive, off-line methods such as the crack-opening method, which is employed as a reference. The methods are utilized in the investigation of the effect of O 2 and N 2 plasma activation and the dilution and temperature of Standard Clean 1 on Si/SiO 2 direct bonding. The results from both methods correlate with each other. The bond strength of the annealed wafers is observed to increase in the order 1) O 2 plasma, 2) standard SC1 at 65 • C, 3) N 2 plasma, and 4) dilute SC1 at 45 • Wafer bonding is an essential component of the semiconductor industry.1-3 It allows wafer level packaging, 3D integration of diverse devices, and manufacturing of silicon-on-insulator (SOI) wafers needed as substrates for microelectromechanical systems (MEMS) and high performance microelectronic and photonic devices.1 Perhaps the most common bonding process used, especially for SOI production, is fusion wafer bonding which usually follows the procedure:First the wafer surfaces are prepared in a cleaning treatment and then the wafers are joined together in vacuum at room temperature. The final bond strength is obtained during annealing at high temperatures. In plasma-activated wafer bonding 3,4 the wafers are pretreated in plasma. This allows high bond strengths to be obtained at lower annealing temperatures.Wet cleaning is an essential step required before fusion bonding of hydrophilic silicon wafers can succeed. The chemistry of Standard Clean 1 (SC1) is a convenient and highly effective method. Numerous early studies such as Refs. 5-8 all used SC1 as part of the standard wafer cleans before wafer bonding. There are three main objectives of the SC1 clean. Firstly, the importance of a hydrophilic surface terminated with hydroxyl groups, readily provided by a basic solution such as SC1, to bonding has long been noted by Maszara et al.,9 and elucidated in detail by Tong and Gösele.8 Secondly, the SC1 clean removes organic contaminants which are known to interfere with bonding reactions.6 Finally, the SC1 clean is very effective at removing particles from wafer surfaces as described in detail by Itano and Kezuka.10 As an additional criteria, roughening of the surface can be minimized with proper dilution of the cleaning solution.9,11 The SC1 clean meets these requirem...

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A physical model to predict stiction in MEMS

Cited by 186 publications

References 23 publications

A physical model to describe the distribution of adhesion strength in MEMS, or why one MEMS device sticks and another ‘identical’ one does not

A physical model to describe the distribution of adhesion strength in MEMS, or why one MEMS device sticks and another ‘identical’ one does not

Vibration of an adhered microbeam under a periodically shaking electrical force

Nondestructive Characterization of Fusion and Plasma Activated Wafer Bonding Using Mesa and Recess Structures

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