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Ohmic contacts

  1. Mar 16, 2009 #1

    Is there someone that can explain why Al can be used to form Ohmic contats to both p- and n-type Si?

    When looking at a Ohmic junction between a metal and a semiconductor, it is formed when the work functions are as follows: [tex]\Phi_m[/tex]>[tex]\Phi_p[/tex] and [tex]\Phi_m[/tex]<[tex]\Phi_n[/tex]. How can Al fulfil both or is there something that I am not aware of?
  2. jcsd
  3. Mar 20, 2009 #2
    Does this help:
    Wikipedia: http://en.wikipedia.org/wiki/Ohmic_contact#Technologically_important_kinds_of_contacts
  4. Mar 26, 2009 #3
    No it does not help.

    I do understand that Al can react with oxygen to form Al2O3 and thereby consum the native oxide. However, this do not explain why Al can make ohmic contact to n- and p-type silicon.
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