This document discusses Micro-Electro-Mechanical Systems (MEMS) technology. It begins with an introduction to MEMS and differences between MEMS and integrated circuits. It then describes basic MEMS elements and the manufacturing processes, including photolithography, micromachining, and laser micromachining. RF MEMS switches are discussed next, including series contact and shunt capacitive switches. Fabrication processes and comparisons with solid state switches are provided. Applications of MEMS in various fields are mentioned. The document concludes that MEMS switches are an alternative to solid state switches due to their low power consumption and high isolation.

1. MEMS TECHNOLOGY
BY:
JAYA NAIK
USN:4NM11EC405
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2. CONTENTS
1.Introduction
2.Differences between IC and MEMS
3.Basic elements of MEMS
4.Manufacturing process of MEMS technology
5.RF MEMS
6.RF MEMS switches
7.Fabrication
8.Comparision of MEMS Switches with solid state
switches
9.Advantages and Disadvantages
10.Applications
11.Conclusion
12.Reference
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3. Introduction
• Micro-Electro-Mechanical Systems
• Miniaturized mechanical and electro mechanical
elements using micro fabrication.
• Most promising Technology of 21st century.
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4. Block diagram of IC+MEMS fabrication
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5. DIFFERENCES: ICs Vs MEMS
MEMS
• 3D complex structures
• Doesn’t have any basic building block
• May have moving parts
• May have interface with external
media
• Functions include
Biological,Chemical,Optical
• Packaging is very complex
ICs
• 2D structures
• Transistor is basic building block
• No moving parts
• Totally isolated with media
• Only Electrical
• Packaging Techniques are well
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6. Basic Functional Elements of MEMS
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7. Manufacturing process of MEMS
Technology
1.Photolithography
2.Silicon Micromachining
a)Bulk Micromachining
b)Surface Micromachining
3.Excimer Laser Micromachining
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8. PHOTOLITHOGRAPHY
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9. Surface Micromachining
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10. Basic techniques of Silicon
micromachining
•Deposition of thin films
•Wet Chemical Etching
•Dry Chemical Etching
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11. Wet Chemical Etching
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12. Lift off
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13. Excimer Laser Micromachining
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14. RF MEMS
•MEMS those with RF range are RE MEMS
•Compound solid state switches have larger
insertion loss(on state) and poor electrical
isolation (off state)
•RF MEMS Switches provides lower insertion
loss, higher isolation, zero static power
consumption
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15. RF MEMS Switches
1.RF series contact switch
2.RF shunt capacitive switch
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16. RF series contact Switch
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17. RF shunt capacitive Switch
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18. Limitations
•Series contact switches tend to fail in the open
circuit.
•Even though the bridge is collapsing and
making the contact with transmission line,
conductivity of contact metallization area
decreases until unacceptable levels of power
losses are achieved
•Shunt capacitive switches often fail due to
charge tapering, both at the surface and bulk
states of the dielectric.
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19. Fabrication
Process flow
(a) Seed layer deposition
(b)Dielectric layer
deposition and patterning
(c) Spacer coater and
patterning
(d)Transmission line
electroplating
(e)Membrane deposition
and patterning
(f)membrane releasing
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20. Comparision of MEMS switches with Solid
State switches
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;PPParameter RFRF MEMS
MEMS
PPIN DIODE FFEFET
Voltage(mA) 20-80 3-5 3-5
Current(mA) 0 0-20 0
Power
consumption
(mW)
0.5-1 5-100 -0.5-0.1
switching 1-300uS 1-100ns 1-100ns
Power
handling(W)
<1 <10 <10
20

21. ADVATAGES OF MEMS
•Can reduce the weight,size,power consumption
and component counts.
•Promise superior performance
•Can be built with high producibility
•New functionality
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22. DISADVANTAGES OF MEMS:-
•Due to their size, significant power
transfer is impossible
•Due to its base material cannot be loaded
with large load
•Design standards are not well developed
•And some Reliability issues..
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23. Applications
•In Navigation field
•Pressure sensors
•Medical field
•High frequency circuits
•Security field
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24. Conclusion
•Low power consumption, high isolation and
ability to integrate with other elements make
MEMS switches an alternative to solid state
switches.
•MEMS is one of the promising technology
•Proper design standards have to be build.
•High performance RF MEMS switches, high
voltage MOSFET and CMOS devices can be
integrated on the same chip.
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25. References
[1] Sazzadur Choudhury, M. Ahmadi, and W.C. Miller, “Micromechanical system
for System-on-Chip Connectivity”, IEEE Circuits and Systems, Page(s) 112-132
September 2002
[2] J. B. Muldavin, G. M. Rebeiz, "High Isolation RF MEMS Shunt Switches-Part
2: Design", IEEE Tran. On Microwave Theory and Techniques, Vol.6, Page(s):
253-276.
June 2000,
[3] P. Osterberg, H. Yie, X. Cai, J. White, and S. Senturia, “Self-consistent
simulation and modeling of RF MEMS,“ in Proc. IEEE MEMS Conf. January 1994,
Page (s)28-32.
[4] Gopinath. A and Ranklin.JB, IEEE Electronic development,” GaAs FET RF
switches “, vol. 12, Page(s) 18-37, August 2003
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26. THANK YOU
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