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Lab 1

The document contains the answers to 5 short questions about semiconductor processing: 1) The acceleration potential determines implantation depth, while beam current and exposure time determine dosage. 2) The correct order of processing steps is: well implantation, field implantation, field oxide growth, poly-silicon deposition and patterning, junction implantation, metal deposition and patterning. 3) A wet oxidation process is faster but results in a lower quality porous oxide, while a dry oxidation process produces a higher density oxide.

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Ahsan Moin
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77 views1 page

Lab 1

The document contains the answers to 5 short questions about semiconductor processing: 1) The acceleration potential determines implantation depth, while beam current and exposure time determine dosage. 2) The correct order of processing steps is: well implantation, field implantation, field oxide growth, poly-silicon deposition and patterning, junction implantation, metal deposition and patterning. 3) A wet oxidation process is faster but results in a lower quality porous oxide, while a dry oxidation process produces a higher density oxide.

Uploaded by

Ahsan Moin
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as DOCX, PDF, TXT or read online on Scribd
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LAB 1

Short Questions

Q1. Discuss briefly the relationship between an ion beam’s acceleration potential, the beam current, and
the time of implantation on the resulting doping profile.

Acceleration potential determines the depth of the implantation; beam current and exposure time
determine dosage.

Q2. Place the processing steps in their correct order: metal deposition and patterning, field
implantation, junction implantation, well implantation, poly-silicon deposition and patterning, field
oxide growth.

Well implantation, field implantation, field oxide growth, poly-silicon deposition and pattering, junction
implantation, metal deposition and pattering

Q.3. what are the major trade-offs in using a wet process or a dry process when growing thermal SiO2?

Wet process faster since water vapor diffuse in Si faster than oxygen gas but lower quality porus oxide
results. Dry process give higher density oxide.

Q.4. Why is poly-silicon used to realize gates of MOS transistors rather than metal?

Poly gates permit a self-aligned process ,eliminating need of another mask. Poly mask defines transistor
channel area.

Q.5. Why can a microcircuit not be annealed after metal has been deposited? Why do we need
annealing in the first place?

Annealing process is a high temperature process ,at high temp metals adversely effected

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