Ion implantation

What is the pair of a vacancy and an interstitial atom called, created in the crystal when an implanted ion knocks a silicon atom out of place?

  1. AFrenkel pair
  2. BCooper pair
  3. CElectron-hole pair
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Answer: A. Frenkel pair

When an implanted ion collides with a silicon atom, the atom is knocked out of its lattice site and becomes an interstitial, leaving a vacancy behind. This vacancy-interstitial pair is called a Frenkel pair. Most of these defects recombine and recover during the post-implant anneal.

  • A. Correct. It is a vacancy-interstitial pair.
  • B. A Cooper pair is a pair of electrons in superconductivity.
  • C. An electron-hole pair is a pair of carriers created by light or similar.
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More Ion implantation questions

  1. Why is the wafer cooled during high-current ion implantation?
  2. What is the typical distribution of crystal damage created by ion implantation?
  3. What method has commonly been used to introduce impurities into a MOSFET's polysilicon gate electrode to lower its resistance?
  4. What is the technique of implanting n-type impurities into an already p-type region to lower the net doping or invert the conductivity type called?
  5. In low-energy implants using decel mode (transporting at high energy and decelerating just before the wafer), what causes the "energy contamination" that requires care?