nmos fabrication

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•nMOS •CMOS for logic • BiCMOS for I/O and driver circuit MOS fabrication process

Transcript of nmos fabrication

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•nMOS•CMOS for logic•BiCMOS for I/O and driver circuit

MOS fabr ication process

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nMOS fabr ication

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Summary of an nMOS process

Depletion mode only

SiO2

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L-Edit layout program

Mask Layout

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• Setup > Technology > MOSIS: Orbit 2U SCNA

Technology Setup

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•Setup > CIF

CIF Layers

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CIF Layer NamesCMOS Poly Gate (CPF)

CMOS Electrode (CPS)

CMOS Active AreaCMOS Metal Fir st

CMOS Metal Second

CMOS Well N-diff

CMOS Select NCMOS Select P

Poly (Poly1)

(Poly2)

Active (Thinox=n-diff + transistor channel)Metal 1

Metal 2

N well

N selectP select

CMOS Contact Poly

CMOS Contact Electrode

CMOS Contact ActiveCMOS Via

CMOS Overglass

Poly contact

Poly2 contact

Active contactVia

Overglass

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(1) Use Layout program (L-Edit) to draw 6 masks of an enhancement mode nMOSprocess by using L-edit and Orbit 2µm double metal, double poly, CMOS technology.

Enhancement Mode NMOS Mask Layout

4λ 4λ 4λ 4λ

28λ

20λ

10λ

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Use CAA (CMOS Active Area) layer to draw a W=28 H=20 rectangular and define the n-diffusion +transistor channel.

Mask #1- CAA

4λ 4λ 4λ 4λ

28λ

20λ

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Mask #2- CPG

4λ 4λ 4λ 4λ

28λ

20λ

10λ

Use CPG (CMOS Poly Gate) layer to draw a W=4 H=24 and a W=8 H=8 rectangulars and define the poly gate.

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4λ 4λ 4λ 4λ

28λ

20λ

10λ

Mask #2 again for n+-diffusion (CSN)

Use CSN (CMOS select N) to draw a W=32 H=24 rectangular for you to select the n-diffusion region within CAA, but not protected by CPG.

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Cross-Section

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4λ 4λ 4λ 4λ

28λ

20λ

10λ

Mask #3- CCP & CCA

Use CCP (CMOS Contact Poly) and CCA (CMOS Contact Active) to draw 5 W=4 H=4 rectangular to open the poly contacts through thick OX

CCP

CCACCA

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Cross Section after Mask #3

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4λ 4λ 4λ 4λ

28λ

20λ

10λ

Mask #4 - CMF

Use CMF to draw metal lines to contact Poly and n-diffusion through CCP and CCA open areas.

CMF

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Cross Section after Mask #4

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Mask #5 – Via layer

Use CVA to draw 3 W=4, H=4 via openings through OX.CVA

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Mask #6 – Overgalss Opening

Use COG to draw 3 W=4, H=4 via openings through Overglass(demo purpose, violate design rules).

COG

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Summary of nMOS Layers

P-doped Si wafer

n+- diffusion n+- diffusionOX

Thin OX

Poly1(CPG)

Overglass

COGCVA

Metal (CMF)OX