1. ECE 875: Electronic Devices
Prof. Virginia Ayres
Electrical & Computer Engineering
Michigan State University

2. Lecture 28, 21 Mar 14
Chp 04: metal-insulator-semiconductor junction: GATES
Q, E , V/y, WD
Capacitances
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3. Example 01 (will be a continuing problem):+
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5. Q E
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6. E (x)
Q(x) = esE (x)
Q (x)
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7. Can easily find E (x) and Q(x) for known yp(x):
Therefore: what yp(x) do we know:
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8. Purpose of a channel in a transistor: binary logic: ON/OFF
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9. ON to OFF: ON: Strong inversion Going OFF: intrinsic
OFF: Strong accumulation
Going OFF: Flatband
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10. OFF to ON: ON: Strong inversion Going OFF: intrinsic
OFF: Strong accumulation
Going OFF: Flatband
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12. Example: What are you trying to find?
What changed from our=Fig 5 example?

13. Answer:

15. Same as in Lec 27: 2 nn0 nn0 3: @ ys for strong inversion 1
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16. Detail: n-channel Debye length LD:
Picture is 2 out of 3:
Missing the holes
Diffusion is hard to stop: holes can diffuse 3D.

17. Detail: Realistic flatband (n-channel):
Miracle
(restrictive)
Evac