The Planar Process

ECE-305: Spring 2016

Basics of Device Fabrication

Professor Mark Lundstrom Electrical and Computer Engineering Purdue University, West Lafayette, IN USA [email protected] Pierret, Semiconductor Device Fundamentals (SDF) pp. 149-174

Lundstrom2/16/16 ECE 305 S16 announcements

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2 Lundstrom ECE 305 S16 integrated circuit resistors

" L % R = ! S $ W ' # & W ! " ! S ( )

P-type 3 N-type Lundstrom ECE 305 S16 lithography

4 Fig. 4.11 from R.F. Pierret, Semiconductor Device Fundamentals Integrated circuit resistors

1) Oxidize 2) Coat with resist

resist SiO2

P-Si

5 Lundstrom ECE 305 S16 Integrated circuit resistors 1) Oxidize 2) Coat with resist 3) Expose light

resist SiO2

P-Si Lundstrom ECE 305 S16 6 Integrated circuit resistors

1) Oxidize 2) Coat with resist 3) Expose 4) Develop

resist SiO2

P-Si Lundstrom ECE 305 S16 7 Integrated circuit resistors

1) Oxidize 5) Etch 2) Coat with resist 3) Expose 4) Develop

resist SiO2

P-Si Lundstrom ECE 305 S16 8 Integrated circuit resistors

1) Oxidize 5) Etch 2) Coat with resist 6) Strip resist 3) Expose 4) Develop

SiO2

P-Si Lundstrom ECE 305 S16 9 Integrated circuit resistors

1) Oxidize 5) Etch 2) Coat with resist 6) Strip resist 3) Expose 7) Dope 4) Develop

P+

SiO2 t L P-Si Lundstrom ECE 305 S16 10 Integrated circuit resistors

1) Oxidize 5) Etch 2) Coat with resist 6) Strip resist 3) Expose 7) Dope 4) Develop 8) Anneal and Oxidize

SiO2 t L P-Si Lundstrom ECE 305 S16 11 Integrated circuit resistors

1) Oxidize 5) Etch 9) Open contacts 2) Coat with resist 6) Strip resist 3) Expose 7) Dope 4) Develop 8) Anneal/Oxidize

SiO2 t L P-Si Lundstrom ECE 305 S16 12 Integrated circuit resistors

1) Oxidize 5) Etch 9) Open contacts 2) Coat with resist 6) Strip resist 10) Deposit metal 3) Expose 7) Dope pattern, etch 4) Develop 8) Anneal/Oxidize

SiO2 t

P-Si Our resistor is also PN junction! Lundstrom ECE 305 S16 13 integrated circuit resistors

" L % R = ! S $ W ' # & W

P-type !S (" !) 14 Lundstrom ECE 305 S16 for more on IC manufacturing

ECE 612 Purdue University:

https://nanohub.org/resources/5788

https://nanohub.org/resources/5855

ECE 557 Purdue University:

15 Lundstrom ECE 305 S16 “The most important moment since humankind emerged as a life form.”

Isaac Asimov

(speaking about the “planar process” used to manufacture ICs -- invented by Jean Hoerni, Fairchild Semiconductor, 1959).

IEEE Spectrum Dec. 2007 16 Lundstrom ECE-305 S16