Jenn: The difficulty that you are having with the removal of the aluminum is likely to be due to a residue layer that forms on the aluminum surface as a result of an interaction between the aluminum and the fluorine in the gas chemistry. This residue layer is not likely to be etchable in the aluminum etchant. In the best case, this residue layer can be removed with a brief oxygen plasma exposure prior to the aluminum etch. Worst case, the residue layer may require a sputter etch or a combination of an oxygen strip and a sputter etch to clean up the surface prior to the aluminum etch. Regards, Robert -----Original Message----- From: mems-talk-bounces+rditizio=tegal.com@memsnet.org [mailto:mems-talk- bounces+rditizio=tegal.com@memsnet.org] On Behalf Of HJ Rhee Sent: Saturday, May 04, 2013 11:00 PM To: mems-talk@memsnet.org Subject: [mems-talk] Remove aluminum mask after DRIE I'm trying to remove the aluminum layer (5000A, sputtered) that was used as a hard mask for DRIE for structure release and having difficulty removing it completely using the Al etchant (Al-12S). There are residues left on the surface (SiO2) that look like small grains, even after leaving the wafer on the ethant (more than 1 hr). After a short-dip on BOE (~30s) and putting in the etchant, the residues are reduced but still not completely clean. Anyone has an idea to completely remove these residues or has the same experience? I don't quite understand why BOE helepd since shouldn't aluminum oxide be only on the surface, not throughout the Al thin-film? Thanks!!! -Jenn _______________________________________________ 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