Lecture 11
Semiconductor Devices
中正大學 化工系
李岱洲
助理教授
Internal Structure of IC Building
Blocks
•Nonlinear I-V characteristics
Diodes
Transistors
•Electric circuits
Passive circuit (resistor, capacitor, or inductor)
Active circuit (contains active circuit element:
transistor))
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Semiconductors
•Crystalline solid materials
with electrical properties
between those of
insulators and conductors
•The most important
semiconductor materials:
Silicon
•Intrinsic semiconductor
very pure semiconductor
http://britneyspears.ac/lasers.htm
•Adding controlled amount of impurities (doping)
→can be made to contain desired numbers of either
holes or free electrons (extrinsic semiconductor
Intrinsic
P-type semiconductor
N-type semiconductor
2
Conductivities of Materials
galileo.phys.virginia.edu/classes/ 315.gbh.fall04/Diode%20Circuits.pdf
•Materials containing primary holes: p-type
semiconductor
(contain very few electrons)
•Materials containing primary electrons: n-type
semiconductor
(contain very few holes)
http://britneyspears.ac/physics/basics/basics.htm
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Semiconductor Junctions
•Combine doping and semiconductor materials,
many different semiconductor junctions can be
form
•Heterojunction:
More than one type of semiconductor forms the
junction region
Diode
•A rectifying device
Convert AC current to DC
current
•Vacuum discharge tube
•Hot filament (cathode)
emits electrons to cold
filament (anode)= one way
traffic (1900)
http://electronics.howstuffworks.com/diode3.htm
4
http://www.allaboutcircuits.com/vol_3/chpt_3/1.html
Electrical Engineering: An Introduction, Steven E. Schwarz and William G. Oldham,
Saunders College Publishing
5
Reverse Bias
Forward Bias
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I-V Characteristics


i I S e qv kT 1
IS: Saturation current
V: Applied voltage
galileo.phys.virginia.edu/classes/ 315.gbh.fall04/Diode%20Circuits.pdf
Ideal Diode Model
galileo.phys.virginia.edu/classes/ 315.gbh.fall04/Diode%20Circuits.pdf
7
Electrical Engineering: An Introduction, Steven E. Schwarz and William G. Oldham,
Saunders College Publishing
8
http://electronics.howstuffworks.com/diode.htm
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