CMOS

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????? ????CMOS
2
??? ????? CMOS
3
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????? ????? ??"? ????? ????? Twin-well ?????
?????? ?????
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????? ????? - LAYOUT
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????? ????? ?? ???????? ???? ????
http//tanqueray.eecs.berkeley.edu/ehab/inv.html.
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A
A
Cross-sections will be shown along vertical
line A-A
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N-well ????? ?-
(1) Oxidize wafer
(2) Deposit silicon nitride
(3) Deposit photoresist
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N-well ????? ?-
(4) Expose resist using n-well
mask
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N-well ?????
(5) Develop resist
(6) Etch nitride and
(7) Grow thick oxide
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N-well ?????
(8) Implant n-dopants (phosphorus)
m
(up to 1.5
m deep)
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P-well ?????
Repeat previous steps
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Grow Gate Oxide
0.055 mm thin
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Grow Thick Field Oxide
0.9 mm thick
Uses Active Area mask
Is followed by threshold-adjusting implants
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Polysilicon layer
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Source-Drain Implants
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Source-Drain Implants
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Contact-Hole Definition
(1) Deposit inter-level dielectric (SiO2) 0.75
mm
(2) Define contact opening using contact mask
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Aluminum-1 Layer
Aluminum evaporated (0.8 mm thick)
followed by other metal layers and glass
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Advanced Metalization