MEMS technology seminar

7/29/2019 MEMS technology seminar

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Micro Electro Mechanical

System [MEMS]TheTechnology

for

Everything!


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Definition

Microelectromechanicalsystems (MEMS) aremicron-size devices thatcan sense or manipulate

the physical world.

MEMS are made up ofcomponents between 10 to100 micrometers in size (i.e.0.01 to 0.1 mm) and MEMSdevices generally range insize from a 20 micrometers(20 millionth of a meter) to amillimeter (thousandth of ameter).
http://en.wikipedia.org/wiki/Meterhttp://en.wikipedia.org/wiki/Millimeterhttp://en.wikipedia.org/wiki/Millimeterhttp://en.wikipedia.org/wiki/Meter


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History of MEMS The invention of the transistor at

Bell Telephone Laboratories in1947 sparked the fast-growing

microelectronic technology

industry.

Jack Kilby of Texas Instruments

built the first integrated circuit (IC)in 1958 using germanium (Ge)

devices.

The first high-volume pressure

sensor was marketed by National

Semiconductor in 1974 - it

included a temperature controller

for constant-temperature operation.

Around 1982, the term

micromachining came into use to

designate the fabrication of moving

micromechanical parts.

First transistor


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History of MEMS

During 1987-1988, a turning point was reached in micromachining

-for the first time, techniques for integrated fabrication ofmechanisms (i.e. rigid bodies connected by joints for transmitting,

controlling, or constraining relative movement) were

demonstrated.

During a series of three separate workshops on micro dynamics

held in 1987, the term MEMS was coined.

First commercialization of MEMS occurred in the 1990s


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Components of MEMS

MEMS can includetwo or more

of the followingsubsystems: sensors,actuators, a power

supply, a centralprocessing unit(CPU)

or microprocessor,and/or acommunicationinterface.


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Materials

Silicon: The economies ofscale, ready availability ofcheap high-qualitymaterials and ability toincorporate electronicfunctionality make siliconattractive for a wide

variety of MEMSapplications.

The basic techniques forproducing all silicon basedMEMS devices aredeposition of materiallayers, patterning of these

layers by photolithographyand then etching to producethe required shapes.

Polycrystalline silicon
http://en.wikipedia.org/wiki/Depositionhttp://en.wikipedia.org/wiki/Photolithographyhttp://en.wikipedia.org/wiki/Photolithographyhttp://en.wikipedia.org/wiki/Deposition


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Materials

Polymers

Polymers on the other hand can be produced in huge volumes, with agreat variety of material characteristics. MEMS devices can be madefrom polymers by processes such as injection moulding, embossingor stereolithography and are especially well suited to microfluidicapplications such as disposable blood testing cartridges.

Metals

Metals can also be used to create MEMS elements.While metals do not have some of the advantagesdisplayed by silicon in terms of mechanical properties,when used within their limitations, metals can exhibitvery high degrees of reliability.

Metals can be deposited by electroplating, evaporation,and sputtering processes.

Commonly used metals include gold, nickel, aluminum,

chromium, titanium, tungsten, platinum, and silver
http://en.wikipedia.org/wiki/Injection_mouldinghttp://en.wikipedia.org/wiki/Embossinghttp://en.wikipedia.org/wiki/Stereolithographyhttp://en.wikipedia.org/wiki/Microfluidichttp://en.wikipedia.org/wiki/Goldhttp://en.wikipedia.org/wiki/Nickelhttp://en.wikipedia.org/wiki/Aluminumhttp://en.wikipedia.org/wiki/Chromiumhttp://en.wikipedia.org/wiki/Titaniumhttp://en.wikipedia.org/wiki/Tungstenhttp://en.wikipedia.org/wiki/Platinumhttp://en.wikipedia.org/wiki/Silverhttp://en.wikipedia.org/wiki/Silverhttp://en.wikipedia.org/wiki/Platinumhttp://en.wikipedia.org/wiki/Tungstenhttp://en.wikipedia.org/wiki/Titaniumhttp://en.wikipedia.org/wiki/Chromiumhttp://en.wikipedia.org/wiki/Aluminumhttp://en.wikipedia.org/wiki/Nickelhttp://en.wikipedia.org/wiki/Goldhttp://en.wikipedia.org/wiki/Microfluidichttp://en.wikipedia.org/wiki/Stereolithographyhttp://en.wikipedia.org/wiki/Embossinghttp://en.wikipedia.org/wiki/Injection_moulding


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How MEMS are made?

There are threebasic buildingblocks in MEMStechnology.

A MEMS process isusually a structuredsequence of theseoperations to formactual devices.

Depositionprocesses

Photolithography

Etching processes


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Deposition processes

One of the basic building blocks inMEMS. MEMS deposition

technology can be classified in two

groups.

1. Depositions that happen because of a

chemicalreaction.

Chemical Vapor Deposition (CVD)

Electrodeposition

Epitaxy

Thermal oxidationThese processes exploit the creation of

solid materials directly from

chemical reactions in gas and/or

liquid compositions or with the

substrate material.

Chemical Vapor Deposition(CVD)


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Deposition processes

Depositions that happenbecause of a physical

reaction: Physical Vapor Deposition

(PVD)

Casting

Common for all theseprocesses are that thematerial deposited isphysically moved on to thesubstrate. In other words,there is no chemicalreaction which forms thematerial on the substrate.

Physical Vapor Deposition


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Photolithography

Lithography in

MEMS context istypically the transfer

of a pattern to a

photosensitive

material by selectiveexposure to a

radiation source

such as light.


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Photolithography

If we selectively expose a

photosensitive material

to radiation the pattern of

the radiation on the

material is transferred to

the material exposed, as

the properties of theexposed and unexposed

regions differs.


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Etching processes

In order to form a functional

MEMS structure on asubstrate, it is necessary toetch the thin filmspreviously deposited and/or

the substrate itself.

There are two basic categoriesof etching processes:

Wet Etching

Wet etching where the material

is dissolved when immersedin a chemical solution.

Wet etching of Si


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Dry Etching

Dry etching where the

material is sputtered or

dissolved using reactiveions or a vapor phase

etchant.

Types of dry etching

Non-plasma based dryetching

Plasma based dry

etching

Dry etching

S i i


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MEMS Fabrication

Techniques

Bulk Micromachining

Surface Micromachining

LIGA


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Bulk Micromachining

Bulk micromachining isthe oldest paradigm ofsilicon based MEMS.

The whole thickness of asubstrate is used forbuilding the micro-

mechanical structures. Bulk micromachining

has been essential inenabling highperformance sensors.

Can be formed by wetand dry etching of Sisubstrate.
http://en.wikipedia.org/wiki/Pressure_sensorhttp://en.wikipedia.org/wiki/Pressure_sensor


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Surface Micromachining

It uses layers deposited

on the surface of a

substrate as the

structural materials,

rather than using thesubstrate itself.

Analog Devices have

pioneered the

industrialization of

surface micromachining

and have realized the co-

integration of MEMS

and integrated circuits.
http://en.wikipedia.org/wiki/Analog_Deviceshttp://en.wikipedia.org/wiki/Analog_Devices


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LIGA

LIGA, a German acronymfor (X-ray) lithography(Lithographie),Electroplating(Galvanoformung), andMolding (Abformung), is a

process in microtechnology. LIGA is a relatively

inexpensive fabricationtechnology.

LIGA is a technology

which creates small, butrelatively high aspectratio devices using x-ray lithography.
http://en.wikipedia.org/wiki/German_languagehttp://en.wikipedia.org/wiki/X-rayhttp://en.wikipedia.org/wiki/Photolithographyhttp://en.wikipedia.org/wiki/Electroplatinghttp://en.wikipedia.org/wiki/Microtechnologyhttp://en.wikipedia.org/wiki/Microtechnologyhttp://en.wikipedia.org/wiki/Electroplatinghttp://en.wikipedia.org/wiki/Photolithographyhttp://en.wikipedia.org/wiki/X-rayhttp://en.wikipedia.org/wiki/X-rayhttp://en.wikipedia.org/wiki/X-rayhttp://en.wikipedia.org/wiki/German_language


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Advantages of MEMS

pp cat ons


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pp cat ons Medical

Micro PowerGeneration

Space

Microcombustion

Automotive

Aeronautical

Communication

Chemical detection

MEMS-BASEDSTORAGE

Micro propulsion Defense


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Medical Applications Disposable Blood

Pressure SensorsMEMS transducer senses

blood pressure through

a silicon-based dielectric

gel between the sensor

and the saline solution. Drug delivery

MEMS devices can be

positioned in the

body by implantation

or by the traditional

pill.


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Medical Applications

MEMS devices firstwere used in medicalapplications in theearly 1970s

MEMS in Surgery

Tissue Sensing: This MEMSprevents cutting of thewrong tissue by sensingthe resistance of thetissue.

MEMS propeller submarine


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Micro applications

Micro Power GenerationGenerate power at the microscale to enable standalone

micro sensors and micro

actuators with wireless

communication Microcombustion

self-sustained combustion in

1 mm3 chamber. Micro Fuel Cells

fabrication of micro fuel cells

with built-in super capacitor &

PdH layer as H2 source


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Automotive Applications

Peripheralacceleration sensor

Oil conditionersensor

Corrosion sensor

GPS and inertialNavigation

Brake pressure andcontrol

Climate control

sensor Suspension control


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Aeronautical Application

Pressure Sensor Belt on

Jet Planes.

It is senses the difference

in air pressure above and

below the wings.

In engines MEMS are

mainly used as the

temperature sensor and

speed sensor.


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Communication Application

RF MEMS

They are new class of

devices and components

with low insertion loss,

high isolation, high Q,

small size, and low powerconsumption; and enable

new system capabilities.

MEMS Microphone Robust

design superior

temperature/humidity

performance


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chemical detection

MEMS fabricationof a mass sensitivegas detector allowsfor integration withCMOS circuitry,potentially leadingto fully integratedsensor arrays ofdifferent physicalmodalities fororganic vapors andbiological agents.


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MEMS-BASED STORAGE

The MEMS fabricationprocess can be integratedwith standard CMOSprocesses, opening thedoor to combineprocessing and

nonvolatile storage. MEMS-based storage

devices could beincorporated into futuredisk drives as very large(1-10 GB) non-volatile

caches.


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Space application

MEMS lowers launchcost by cutting the massof components onboardthe space vehicle.

Cosmic radiation canupset the operation of

solid state components,but MEMS structurescan withstand radiation.

MEMS can be used todesign satellites of mass1-10 kg classified asnanosatellites and 1kgsatellites aspicosatellites.

MEMS i D f


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MEMS in Defense Cyborg insects with

MEMS that will runremotely controlled

reconnaissance missionsfor the military. MEMSsensors, such as videocameras, audiomicrophones, andchemical sniffers so thatthey could move intoenemy territory inswarms to performreconnaissance missionsotherwise dangerous forsoldiers.

Smart dust: A tiny

wireless sensors(MEMS), robots anddevices, installed withwirelesscommunications, that candetect anything fromlight and temperature tovibrations.

Cyborg insect and Smart dust

MEM current c a enges


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MEM current c a enges Although some products

like pressure sensors havebeen produced for 30 years,MEMS industry in manyaspects is still a young

industry. The relatively long

development cycle for aMEMS component is also ahurdle that needs to belowered if we want morecompany to embrace the

technology. short introduction has

shown that specific trainingis needed for MEMSengineers, whereknowledge of mechanicaland material engineering

supplements electronicengineering.

Considering the smallermarket size of most MEMScomponent, standard is theonly way to bring thenumbers where unit

packaging price is reducedsubstantially.


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Future trend of MEMS Looking in the crystal ball for

MEMS market has shown to

be a deceptive work, butcurrent emerging tendenciesmay help foresee what willhappen in the medium term.

lowering manufacturing cost

will hopefully result instandardization of the MEMSinterfacing.

From the market side, MEMSwill undoubtedly invade moreand more consumer products.

A farthest opportunity forMEMS lies probably innanotechnology.

Combination withnanotechnology and

biotechnology


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Conclusion

By looking at all the

applications wecan say that

"There's plenty

of room atthe bottom"!

R f


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Reference www.memsnet.org

www.mems.sandia.gov

www.csa.com/discoveryguides/mems/overview.php

www.ee.udel.edu

clifton.mech.northwestern.edu

www.darpa.mil/MTO/MEMS

robotics.eecs.berkeley.edu/~pister/SmartDust

www.arri.uta.edu

www.eng.tau.ac www.inrf.uci.edu

www-micrel.deis.unibo.it

www. wps2a.semi.org

www.fys.uio.no

www. esamultimedia.esa.int www.matec.org

www.stormingmedia.us

www.mrs.org

www. fy.chalmers.se


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Thank you

!!!!!!

MEMS technology seminar

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