Ion implantation

Which correctly pairs dopants implanted into silicon with the conductivity type they produce?

  1. APhosphorus: p-type; arsenic: p-type
  2. BBoron: n-type; phosphorus: p-type
  3. CBoron: p-type; phosphorus and arsenic: n-type
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Answer: C. Boron: p-type; phosphorus and arsenic: n-type

Group III boron acts as an acceptor and produces p-type silicon, while group V phosphorus and arsenic act as donors and produce n-type. Ion implantation places the required amount of these elements where they are needed.

  • A. Both phosphorus and arsenic produce n-type.
  • B. The types for boron and phosphorus are reversed.
  • C. Correct. Boron gives p-type; phosphorus and arsenic give n-type.
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More Ion implantation questions

  1. Which is closest to the range of ion implantation doses used in LSI manufacturing?
  2. What is the main reason the beam path in an ion implanter is kept at high vacuum?
  3. In a typical ion implanter, in what order do ions pass through the system?
  4. When implanted into silicon at the same energy, how do the ranges of arsenic (mass 75) and phosphorus (mass 31) compare?
  5. In an ion implanter, what is the energy of a doubly charged ion (twice the charge) accelerated through 50 kV?