Manufacturing Processes for Engineering Materials (5th Edition in …ma.gnu.ac.kr/course/mp/13_Micro.pdf · 2019-11-25 · Manufacturing Processes Micro-manufacturing • Manufacturing

© Pearson & GNU Su-Jin Kim

MEMS

Manufacturing Processes


Micro Fabrication

Associate Professor Su-Jin Kim

School of Mechanical Engineering

Gyeongsang National University

http://ma.gnu.ac.kr/

http://engine.gnu.ac.kr/

http://www.gnu.ac.kr/


MEMS


OCW

• CPU manufacturing: https://youtu.be/UvluuAIiA50

• MEMS: https://youtu.be/iPGpoUN29zk

https://youtu.be/UvluuAIiA50

https://youtu.be/iPGpoUN29zk


MEMS


Index

• Micro fabrication of IC(Integrated Circuits) 반도체제조1. Weiper(웨이퍼)

2. Lithography(노광)

3. Etching(식각)

4. Doping(확산)

5. Deposition(증착)

6. Packaging(포장)

• MEMS(Microelectromechanical system) 미소기전


MEMS


Micro-manufacturing

• Manufacturing on a microscopic scale

• IC: Integrated circuit

• MEMS: micro electro mechanical system

• Products

1. Sensors

2. Inkjet printing heads

3. Micro-actuators

4. Hard-drive heads

5. Computer processors

6. Memory chips


MEMS


Transistor to IC

• Transistors(1947) IC (integrated circuits), MOS (metal-oxide-semiconductor) VLSI (very large-scale integration)

• Moore’s Law : The number of transistors per chip doubles every 18 months.

Transistor IC


MEMS


Clean Rooms

• Essential for the production of IC (integrated circuits).

• Cleanliness are defined by class of the clean rooms.

• Air is passed through a high-performance particulate air (HEPA) filter.

• Largest source of contaminants is people.


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P

-

-

--

-

B

-

--

Si

-

-

--

Silicon (Semiconductors)

• Natural silicon dioxide SiO2 is an excellent insulator.

• Single crystal silicon Si is semiconductor.

• Get n-type by doping P or p-type doping B.

SiO2

Insulator Single crystal silicon n-type p-type

+phosphorus +boron


MEMS


Integrated Circuits; IC Process

Wafers

DepositionFilm deposition

Oxidation

LithographyCoat photoresist

Photolithography

Remove exposed photoresist

Etching

Doping

Wet etching

Dry etching

Diffusion

Ion implantation

DeviceWire bonding

Packaging

Ingot

Wafer

https://youtu.be/qm67wbB5GmI CPU Fab (10 min)

https://youtu.be/_8HwIHyVD1E Hynix Kr (5min)

https://youtu.be/qm67wbB5GmI

https://youtu.be/_8HwIHyVD1E


MEMS


Ingot & Wafer

1. natural SiO2 purification electric-grade silicon Si

2. Single-crystal silicon ingot is grown from the purified silicon melt.

3. The Ingot is cut into silicon wafers. The wafers are polished until they have mirror-smooth surfaces.

Wafer: http://www.youtube.com/watch?v=LWfCqpJzJYM&feature=related

http://www.youtube.com/watch?v=LWfCqpJzJYM&feature=related


MEMS


Lithography 노광

1. Drop down photoresist on spinning wafer.

2. Photolithography : UV light passes through mask to wafer surface.

3. Exposed photoresist is dissolved by a solvent.

Photolithography: http://www.youtube.com/watch?v=9x3Lh1ZfggM&feature=related

http://images.google.co.kr/imgres?imgurl=http://blogfiles2.naver.net/data17/2007/6/13/161/9-mickyblue.jpg&imgrefurl=http://basetec.egloos.com/&usg=__rWELsH2Dwg6i72hA7y6pDQN4gYk=&h=334&w=380&sz=19&hl=ko&start=15&um=1&tbnid=E7bWoiGqmXd8yM:&tbnh=108&tbnw=123&prev=/images%3Fq%3DWafer%2Bcoated%2Bphotoresist%26complete%3D1%26hl%3Dko%26lr%3D%26sa%3DG%26um%3D1%26newwindow%3D1

http://www.youtube.com/watch?v=9x3Lh1ZfggM&feature=related


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Etching 식각

1. The photoresist protects material not be etched away in an acid solution.

2. After the etching the photoresist is removed and the desired shape becomes visible.

scale: transistor level (~50-200nm)

IC Process: Photoresist, Lithography, Etching, Doping, Deposition

http://www.youtube.com/watch?v=26fkuAY8jKs&feature=related(4min)

http://www.youtube.com/watch?v=26fkuAY8jKs&feature=related


MEMS


Doping 확산

1. The photoresist (blue) will protect material that should not get ions implanted.

2. In Ion implantation, ions accelerate through a high-voltage beam and impact on the exposed areas (green) of the silicon wafer.

3. After the ion implantation the photo resist is removed

4. Operation of microelectronic devices depends on different doping types and concentrations.


MEMS


Deposition 증착

1. Three holes have been etched into the insulation layer (magenta color) above the transistor.

2. The wafers are put into a copper sulphate solution. The copper ions are deposited onto the transistor thru a process called electroplating.

3. On the wafer surface the copper ions settle as a thin layer of copper.

4. The excess material is polished off. Three holes are filled with copper which will make up the connections to other transistors.

PVD: http://www.youtube.com/watch?v=dpwIswozTdw&feature=related (30s)

http://www.youtube.com/watch?v=dpwIswozTdw&feature=related


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Metallization & Testing

1. Metallization: Devices are interconnected by multiple metal layers (Al, Cu).

2. Testing: Test each of the individual circuits with probe

3. The wafer is cut into pieces called dies.


MEMS


Wire Bonding and Packaging 포장

1. Working dice is attached to a rugged foundation with epoxy or eutectic bond.

2. Chip is electrically connected to the package lead by thermo-sonic wire bonding.

3. Package: The green substrate, the die and the silver heat-spreader are put together to form a completed processor.

Packaging m. p.: http://www.youtube.com/watch?v=Cg-mvrG-K-E&feature=related

http://www.youtube.com/watch?v=Cg-mvrG-K-E&feature=related


MEMS


Printed Circuit Boards; PCB

• Packaged integrated circuits are combined with other ICs as building blocks for a larger system.

• Printed circuit board (PCB) is the substrate for the final interconnections.


MEMS


MEMS Devices

• The MEMS(Microelectromechanical systems) devices can be made through the IC Process:

• Bulk micromachining: Pressure sensor

• Surface micromachining: Accelerometer

http://www.youtube.com/watch?v=ZuE4oVrtEQY

http://www.youtube.com/watch?v=ZuE4oVrtEQY


MEMS


Bulk micromachining

• Mask pattern by SiO2 or Si3N4

• Etching silicon substrate

• Pressure sensor


MEMS


Surface micromachining

Micro-cantilever

1. Silicon substrate, Si

2. Deposit silicon nitride, Si3N4

3. Grow silicon oxide, SiO2

4. Pattern by Lithography

5. Deposit polysilicon

6. Remove SiO2 by Etching


MEMS


Accelerometer for airbags

• Acceleration Displacement of beam Capacitive change Turn on the airbag


MEMS


Comb Drive / Capacitive

• Parallel Plate Capacitor

C = ε A/d

• Electrostatic Force

Fe = ½ ε (A/d2)V2

Documents

Manufacturing Processes for Engineering Materials (5th Edition in …ma.gnu.ac.kr/course/mp/13_Micro.pdf · 2019-11-25 · Manufacturing Processes Micro-manufacturing • Manufacturing