[sci.physics] Ohmic Contacts to n-AlGaAs

berryh@udel.edu (John Berryhill) (01/12/90)

I'm having some trouble with contacts on n-AlGaAs (x=.1 or so).
I'm depositing about 5000 Angstroms of Au-Ge alloy (12% Ge) and
following that with 1000A of nickel.  Some of the time, it works
just fine, but too often the contacts tend to ball up when I'm
alloying them to the AlGaAs layer.  As I understand it, the purpose
of the Ni layer is to keep that from happening.  Is there something
else I should be doing in addition to the Ni to prevent it from
balling up?

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							      John Berryhill
					   143 King William, Newark DE 19711