8/8/2019 050906_lecture2

1/27

7

CMOS Fabrication

p-substrate

SiO2

photoresist

Oxidize silicon surface and coat with photoresist

ORNELLC

8/8/2019 050906_lecture2

2/27

7

CMOS Fabrication

p-substrate

ultraviolet light

mask

Pattern and selectively etch oxide layer

ORNELLC

8/8/2019 050906_lecture2

3/27

7

CMOS Fabrication

p-substrate

ion implant

SiO2

photoresist

Ion implant for n-well regions

ORNELLC

8/8/2019 050906_lecture2

4/27

7

CMOS Fabrication

p-substrate

SiO2n-well

Anneal n-well implant and grow oxide

ORNELLC

8/8/2019 050906_lecture2

5/27

7

CMOS Fabrication

SiO2

nitride

p-substrate

n-well

Remove all oxide, regrow thin oxide, and deposit nitride layer

ORNELLC

8/8/2019 050906_lecture2

6/27

7

CMOS Fabrication

SiO2nitride

p-substrate

n-well

Pattern and selectively etch oxide and nitride layers

ORNELLC

8/8/2019 050906_lecture2

7/27

7

CMOS Fabrication

SiO2

nitride

p-substrate

n-well

Grow field oxide in areas without nitride

ORNELLC

8/8/2019 050906_lecture2

8/27

7

CMOS Fabrication

field oxide

polysilicon

p-substrate

n-wellgate oxide

Remove nitride and thin oxide, grow gate oxide, and deposit poly

ORNELLC

8/8/2019 050906_lecture2

9/27

7

CMOS Fabrication

p-substrate

n-well

polysilicon

Pattern and selectively etch polysilicon

ORNELLC

8/8/2019 050906_lecture2

10/27

7

CMOS Fabrication

p-substrate

n-well

photoresist

Conformally coat entire surface with photoresist

ORNELLC

8/8/2019 050906_lecture2

11/27

7

CMOS Fabrication

p-substrate

n-well

Remove photoresist to expose regions for n+ implant

ORNELLC

8/8/2019 050906_lecture2

12/27

7

CMOS Fabrication

p-substrate

n-well

n+implant

Ion implant for n+ regions and remove all photoresist

ORNELLC

8/8/2019 050906_lecture2

13/27

7

CMOS Fabrication

p-substrate

n-well

photoresist

Conformally coat entire surface with photoresist

ORNELLC

8/8/2019 050906_lecture2

14/27

7

CMOS Fabrication

p-substrate

n-well

Remove photoresist to expose regions for p+ implant

ORNELLC

8/8/2019 050906_lecture2

15/27

7

CMOS Fabrication

p-substrate

n-well

p+implant

Ion implant for p+ regions and remove all photoresist

ORNELLC

8/8/2019 050906_lecture2

16/27

7

CMOS Fabrication

SiO2

p-substrate

n-well

Deposit thick oxide layer over entire surface

ORNELLC

8/8/2019 050906_lecture2

17/27

7

CMOS Fabrication

SiO2

p-substrate

n-well

n+

p+

p+

n+

Anneal and drive in both implants

ORNELLC

8/8/2019 050906_lecture2

18/27

7

CMOS Fabrication

SiO2

p-substrate

n-well

Planarize surface by chemical-mechanical polishing

ORNELLC

8/8/2019 050906_lecture2

19/27

7

CMOS Fabrication

contact holes

p-substrate

n-well

Open contact windows in the oxide

ORNELLC

8/8/2019 050906_lecture2

20/27

7

CMOS Fabrication

metal1

p-substrate

n-well

Fill contact holes with metal and deposit metal1

ORNELLC

8/8/2019 050906_lecture2

21/27

7

CMOS Fabrication

metal1

p-substrate

n-well

Pattern and selectively etch metal1

ORNELLC

8/8/2019 050906_lecture2

22/27

7

CMOS Fabrication

SiO2

p-substrate

n-well

metal1

Deposit thick oxide layer over entire surface

ORNELLC

8/8/2019 050906_lecture2

23/27

7

CMOS Fabrication

SiO2

p-substrate

n-well

metal1

Planarize surface by chemical-mechanical polishing

ORNELLC

8/8/2019 050906_lecture2

24/27

7

CMOS Fabrication

p-substrate

n-well

via holes

Open via windows in the oxide

ORNELLC

8/8/2019 050906_lecture2

25/27

7

CMOS Fabrication

p-substrate

n-well

metal2

Fill via holes with metal and deposit metal2

ORNELLC

8/8/2019 050906_lecture2

26/27

7

CMOS Fabrication

p-substrate

n-well

metal2

Pattern and selectively remove metal2

ORNELLC

8/8/2019 050906_lecture2

27/27

7

CMOS Fabrication

p-substrate

n-well

metal2

SiO2

Deposit thick oxide layer over entire surface

ORNELLC