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Homework Help: Microelectronics HW question

  1. Oct 9, 2013 #1
    Design a rectangular bpiece of Silicon with n = 300cm^-3 at T = 300K. Be specific and quantitative

    n*p = ni^2
    ni = 5.2 × 1015T3/2 e^(−Eg/2kT) electrons/cm^3

    Using the formula above, with Eg = 1.12eV = 1.792x10^-19 J, and k = 1.38x10^-23
    i get ni = 1.0776x10^10 electrons/cm^3
    Using the formula n*p = ni^2, i solved for p = 3.87x10^17

    As far as where to go next, I'm unsure. I sent a message to my prof. asking what exactly he wants for this question, but I haven't received a response yet. Would it be even feasible to attempt to get dimensions for a solid using just these values?
  2. jcsd
  3. Oct 10, 2013 #2


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    Staff: Mentor

    Your p needs units.
    I don't see how the size would be relevant here, unless there is something missing in the problem statement. You have to get a certain electron density, and this is independent of the size.
    Last edited: Oct 10, 2013
  4. Oct 10, 2013 #3
    I got a message back from the prof. Turns out he was mostly just wanting to know what process would be used to actually make a piece of Si with n and p such as this. Essentially, he just wants to know what process of doping I would use. Oh well, I was pulling my hair out for nothing.
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