Hi All,

I have electroplated copper (0diameter 100 um) in silicon wafer (300 um) by
'bottom up electroplating'. Bottom wafer has 300 nm thick gold seed layer.
bottom seed layer is bonded with top silicon wafer by photoresist.

Now my problem is - i am not able to seprate these two wafers. Electroplated
copper forms inter-metallalic bond with copper. I tried to seprate these
wafers by putting them in ultrasonic agitator with acetone, but could not
get any success.

Can any one suggest any way/trick to seprate top silcion wafer with bottom
(gold seed layer) wafer ? does gold etchant etch copper also ? If yes, what
is the selectivity ?

Thanks in advance.
Pradeep Dixit