Hi Jack,

What is typical would be to do a very dilute acid dip directly prior to
going into the plating bath.  This will remove the copper.  You could try
one of the following based on your process needs:  5% Acetic, 5% HCL, 2%
Sulfuric.  Transfer the wafers from the acid to a DI rinse but don't dry the
wafers before going into the plating bath.  it helps if the wafer and
cathode arrangement can be dipped into the acid, that way you minimize the
time between acid-rinse-plate steps.

If your process shows some non-uniformity of copper oxide removal before
plate, another trick is to run a low-power O2 descum prior to the acid dip.

Regards,
Justin



-----Original Message-----
From: Jack Peng [mailto:[email protected]]
Sent: Monday, October 18, 2004 1:09 PM
To: [email protected]
Subject: [mems-talk] seed layer for nickel elctroplating


Hi Sreeram,
        I am trying to plate copper on top of chrome and copper. I am
worried about oxidation of the copper seed layer before plating. Should I
treat the copper seed layer with some chemical?
        Thanks.

Jack




---original message----
Hey Ashari

   Aluminum is soluble in both acidic and basic solutions and is not an
ideal seed layer. The typical seed layer used for electroplating is titanium
followed by copper.

   Regards
   Sreeram

-----Original Message-----
From: mems-talk-bounces+sappasam=ececs.uc.edu at memsnet.org

[mailto:mems-talk-bounces+sappasam=ececs.uc.edu at memsnet.org
 ] Sent: Tuesday,
December 16, 2003 2:59 AM
To: mems-talk at memsnet.org

Subject: [mems-talk] seed layer for nickel elctroplating

Is there a way to electroplate nickel onto aluminium
coated wafer as im unable to do so currently. Whats
the best seed layer for nickel electroplating.

=====
ashari keling




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