The authoritative public forum
  for Metal Finishing since 1989
-----

How to migrate and remove copper from silicon wafers

If you had a copper doped silicon wafer and you wanted to drive the copper to either the top or bottom side of the wafer for purposes of removing the Cu ions through a chemical/mechanical process, how would you do this? Could you use an anode plate and a cathode plate to sandwich the wafer in between the two and drive the copper ions to one side or the other? What type of material would the anode and cathode need to be made out of, how much electricity would be required and how would you do this in a fashion to make this process happen as rapidly as possible?

Thanks,

Gary Conrad Barret
President and CEO - Dallas, Texas, U.S.A.
2007

---

Unfortunately, none of our readers have replied, Gary. I'm assuming it's because they see this question as one of electronics fabrication, which as metal finishers they may not really be familiar with. Sorry.

We are used to aqueous processes and it seems that your needs would be met (if at all) by applying the electricity during some kind of high temperature high vacuum process; I assume that the copper doping must be very stable and resistant to migration at normal conditions or semiconductors would not be useful and reliable :-)

Good luck.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2007