Doping
Beginner
Mixing a tiny pinch of another element into silicon so that it carries electricity in a controlled way.
Novice
Introducing impurity atoms into silicon. Donors such as phosphorus or arsenic add free electrons (n-type); acceptors such as boron add holes (p-type). Heavily doped regions are marked n+ or p+.
Expert
Doping sets the body’s carrier concentration and hence the threshold voltage; separate threshold-adjust implants produce the low-, standard- and high- device flavors of one process.