Hello dear MEMS-Talk members!

We are trying to electroplate 20-um thick copper over patterned 4-inch wafers.
The problem is the uniformity of the Cu layer. If it is approx. 20 um
in the middle of the wafer then we have something like 25 um at the
edges.

I found out that there is a device called an IBM Paddle Cell. Does
anybody know anything about it? Is it of help in this case? Is there
any other practical solution.
We tried the rotating cathode method and we tried to agitate the
solution with the rotating paddle. Did not help.

Thank you!

--
M.Sc. Denis Petrov
Ph.D. Student

Institute for Microsensors, -actuators and –systems (IMSAS)
University of Bremen, Dept. 1: Physics / Electrical Engineering
Otto-Hahn-Allee, Build. NW 1, Room N 2160
D-28359 Bremen, Germany

Phone: +49 (0)421 218 - 3244
Fax: +49 (0)421 218 - 4774
E-Mail: dpetrov@imsas.uni-bremen.de
http://www.imsas.uni-bremen.de

IMSAS is member of the Microsystems Center Bremen (MCB)
http://www.mcb.uni-bremen.de