No, I don't think so. I electroplate a wafer with 2.5 microns of gold. Then I apply a photomask, and electroplate 1 micron of nickel and another 2.5 microns of gold. In an Iodide etch, the nickel is very clearly etched from the outside in. If left long enough, (just a few minutes, not enough to etch through the gold), the top gold piece will simply lift off. There is no nickel left attached either to the top gold piece or the bottom gold piece. Thinner parts of the pattern lift off first, as the nickel is attacked from the edges in. I only got attack of nickel on gold when the nickel was deposited by electroless deposition, which tends to give a porous and soft nickel. Electroplated nickel almost always seemed to be good. David Nemeth Senior Process Engineer Sophia Wireless, Inc. 14225-C Sullyfield Circle Chantilly, VA Ph: (703) 961-9573 x206 Fax:(703) 961-9576 -----Original Message----- From: mems-talk-admin@memsnet.org [mailto:mems-talk-admin@memsnet.org]On Behalf Of Neal Ricks Sent: Monday, September 09, 2002 3:33 PM To: mems-talk@memsnet.org Subject: RE: [mems-talk] Nickel etchant David, The KI/I mix is a Gold etchant, so could the effect you've seen be the result of access to the Gold (i.e. pinholing, lift-off, or undercut of the Nickel), rather than an electrochemical effect? Neal David Nemeth wrote:In my experience, this solution will not attack Nickel that is not in contact with another metal. It will aggressively attack nickel that is sandwiched between two layers of gold (don't ask me why - go ask an electrochemist). It will sometimes attack nickel that is on top of gold, depending on the deposition method of the Nickel. David Nemeth Senior Process Engineer Sophia Wireless, Inc. 14225-C Sullyfield Circle Chantilly, VA Ph: (703) 961-9573 x206 Fax:(703) 961-9576 -----Original Message----- From: mems-talk-admin@memsnet.org [mailto:mems-talk-admin@memsnet.org]On Behalf Of Phaneendra Medida(fabbi) Sent: Monday, September 09, 2002 2:47 PM To: mems-talk@memsnet.org Subject: [mems-talk] Nickel etchant Does this solution (KI(Potassium iodide)+I2(Iodine)+Water) Etch Nickel? Fabbi.