Engineering Electromagnetics 1 0909'301'01 Fall 2004

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Engineering Electromagnetics 10909.301.01 Fall
2004
INTRODUCTION TO MOSFETSOctober 6, 2004

• Linda Head
• ECE Department
• Rowan University
• http//engineering.rowan.edu/shreek/fall04/eemag1
  /lectures/mosfets.ppt

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Silicon - Four Cases
Intrinsic Si - 0oK
Intrinsic Si - Room Temp
N-type Si
P-type Si
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Metal-Oxide-SemiconductorCapacitor
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Looks Like.
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The positive charge on the metal is matched by
negative charge from the ions in the p-type
semiconductor. The h just get pushed away from
the interface between the insulator and the
p-type semiconductor leaving only the stuck
charged atoms. We call this the depletion region
- we now have a 2-layer insulator.
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Once a maximum width is reached for the
depletion region the electrons in the material
are attracted to the SiO2 / p-type Si interface
and now there is an channel of electrons right
underneath the SiO2
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MOSFET Operating Regions
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Depletion Region
0.4 V
0 V
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Inversion Region
0 V
1.0 V
0 V
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Linear Region
1 V
0.25 V
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Pinch-Off Region
1 V
1.5 V
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Things You Need To Know

• ?r(Si) 11.8 ?r(SiO2) 3.9
• The length of the channel is 1.
• The n source and drain, the polysilicon and the
  p semiconductor are metal-like conductors.