Ion implantation

What is an advantage of plasma doping, in which the wafer is exposed directly to a dopant-containing plasma and implanted with low-energy ions?

  1. AMass analysis can accurately select only the desired ions
  2. BHigh doses at low energy are easy, and 3D structures can be doped relatively uniformly
  3. CIt is suited to deep, high-energy implants
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Answer: B. High doses at low energy are easy, and 3D structures can be doped relatively uniformly

Unlike beam-scanning implanters, plasma doping exposes the whole wafer to ions at once, so high doses can be implanted at low energy in a short time. Ions and radicals arrive from various directions, which also makes it easier to dope the sidewalls of 3D structures such as fins.

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More Ion implantation questions

  1. When implanting with the wafer tilted, what is the phenomenon called in which areas in the shadow of tall patterns such as resist receive no implant?
  2. When dopants are activated by annealing, which property sets the upper limit of the concentration that can be electrically activated?
  3. Which is a characteristic of laser annealing?
  4. In ion implantation, how is the dose made uniform across the wafer?
  5. In an ion implanter, which component measures the beam current to determine the number of implanted ions (dose)?