1. EE 5340 Semiconductor Device Theory Lecture 20 - Fall 2010
Professor Ronald L. Carter

2. EE 5340 Test 2 – 11 AM – 3Nov 108 Nedderman Hall
Procedure as for Test 1
Will cover
Chapters 4, 5, and 6.
Problems assigned for 4, 5, and 6.
Lectures 11 through 20
Cover Sheet draft and Test Instructions will be posted at
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3. npn BJT topology x x’ p-Base n-Collector N-Emitter z WB WB+WC -WE x”c
Charge Neutral Region
Depletion Region x x’
p-Base
n-Collector
N-Emitter z WB
WB+WC
-WE
x”c x” xB
x’E IE IC IB
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4. IC npn BJT (*Fig 9.2a)
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5. npn BJT bands in FA region
q(VbiE-VBE )
q(VbiC-VBC )
qVBE
qVBC
injection
high field
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6. npn BJT regions of operation
VBC
Reverse Active
Saturation
VBE
Forward Active
Cutoff
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7. npn FA BJT minority carrier distribution (Fig 9.4*)
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8. npn RA BJT minority carrier distribution (Fig 9.11a*)
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9. npn cutoff BJT min carrier distribution (Fig 9.10a*)
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10. npn sat BJT minority carrier distribution (Fig 9.10b*)
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11. npn BJT currents (F A region, ©RLC)
IC = JCAC
IB=-(IE+IC )
JnE
JnC
IE =
-JEAE
JRB=JnE-JnC
JpE
JGC
JRE
JpC
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12. E current equations mode npn BJT (w/o gen/rec)
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13. C current equations in npn BJT (w/o gen/rec)
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14. Recombination/Generation Currents (FA)
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15. FA npn figure of merit – emitter efficiency
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16. FA npn figure of merit – base transport factor
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17. FA npn figure of merit – recombination factor
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18. Common base current gain, aFaT d
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19. Common base current gain, aF (continued)
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20. Common emitter current gain, bF
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21. References
* Semiconductor Physics and Devices, 2nd ed., by Neamen, Irwin, Boston, 1997.
**Device Electronics for Integrated Circuits, 2nd ed., by Muller and Kamins, John Wiley, New York, 1986.
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