Thanks Andre for the nice reply. It was really important. But is it possible that two TMAH based developer will behave differently on contact with copper seed (One forms complex with Cu while the other does not), even though TMAH content is same? Many Thanks, Ricky -----Original Message----- From: mems-talk-bounces+ricky.anthony=tyndall.ie@memsnet.org [mailto:mems-talk- bounces+ricky.anthony=tyndall.ie@memsnet.org] On Behalf Of André Bödecker Sent: 01 October 2013 06:16 To: mems-talk@memsnet.org Subject: [mems-talk] TMAH reaction with copper Hi Ricky, copper has a chemical affinity to form a bond with the free electron pair of nitrogen in nitrogen-containing compounds like ammonia ( by forming this: [Cu(NH3)4]2+) or its derivative TMAH. I'm not sure if sterically possible for TMAH to form a fourfold tetramethyl ammonium complex with copper or if it's only a twofold. There is always a slight oxidation of copper under the presence of oxygen. If there is also such a nitrogen-compound, you will have a reaction as described above. Best regars/Mit freundlichem Gruß André Bödecker Institut für Mikrosensoren, -aktoren und -systeme Universität Bremen Fachbereich 1 Otto-Hahn-Allee1 28359 Bremen Tel: 0421 218 62596 _______________________________________________ Hosted by the MEMS and Nanotechnology Exchange, the country's leading provider of MEMS and Nanotechnology design and fabrication services. Visit us at http://www.mems-exchange.org Want to advertise to this community? See http://www.memsnet.org To unsubscribe: http://mail.mems-exchange.org/mailman/listinfo/mems-talk _______________________________________________ Hosted by the MEMS and Nanotechnology Exchange, the country's leading provider of MEMS and Nanotechnology design and fabrication services. Visit us at http://www.mems-exchange.org Want to advertise to this community? See http://www.memsnet.org To unsubscribe: http://mail.mems-exchange.org/mailman/listinfo/mems-talk