Some years ago when I worked on the Gravity Probe-B project we did wire
bonding to Nb superconducting circuits.  For this application a thin
layer of Au was sputtered on the Nb in situ immediately after sputtering
the Nb.  A Pb/In/Au wire was then ultrasonically bonded to the Au.  (The
Au film was thin enough that a superconducting contact was established
between the wire and the Nb.)  However if you don't need a
superconducting connection, Au bond wire will work well with this
system.  You can probably use Al wire with the right metallization, but
I think native oxide will make it difficult to bond directly to the Nb.

Roger Shile

-----Original Message-----
From: mems-talk-bounces+rshile=nanoink.net@memsnet.org
[mailto:mems-talk-bounces+rshile=nanoink.net@memsnet.org] On Behalf Of
Jie Zou
Sent: Thursday, June 02, 2011 8:51 AM
To: General MEMS discussion
Subject: [mems-talk] Bonding gold to Niobium?

Hi, folks,

I know it is the best to use Al as the bonding wires for Niobium.
Unfortunately we don't have a Al bonder. Anyone have experience with
bonding
gold to Niobium?

Or, can I evaporate gold on the Nb at the bonding area and then do the
bonding?

Any care I need to take in order to let the gold and Nb adhere and
conduct
well?

Thanks.

*  Zou Jie (Jay)
*  Department of Physics
*  University of Florida
*  Email: zoujiepku@gmail.com