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What is n+, p+, p doping?

  1. Aug 6, 2010 #1
    I'm reading an article that has n+, p+, and p doped silicon wafers.
    I hadn't heard of n+ or p+ before, just n and p. I noticed in the article that n+ and p+ had really low resistivites (10^-2 Ohm-cm) and p had a resistivity of about 10 Ohm-cm.

    So does the plus sign just mean it is heavily doped or is there a different meaning to the + sign?
    Last edited by a moderator: Apr 25, 2017
  2. jcsd
  3. Aug 6, 2010 #2


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    Yes, the plus sign refers to "extrinsic" doping such that the material is highly conductive. This is used typically in the outer layers of p-i-n diodes. By contrast, the i layer is "intrinsic," or undoped and highly resistive.
    Last edited: Aug 6, 2010
  4. Aug 6, 2010 #3


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    I usually use n+ and p+ for Si that is doped heavily enough that the resistivity is down in the range of milliOhm-cm. When it's greater than an Ohm-cm, I call it n or p type. I think that's not completely inconsistent with the literature.
  5. Aug 9, 2010 #4
    Great. Thanks so much!
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