Hi, When the mixture( 3 parts H2O2 and 1 part NH4OH) cooled down, the Au-layered glass was inserted into the solution. Immediately many bubbles came out. Did it indicat Au was reacting with the solution? There were something modified chemically on the Au film before processing. I want to clear up the modified film and get smooth and naked Au. Would you give me some advice that will not etch Au? Thanks a lot! Laura W > Hi, > > The following solution is great for cleaning a Gold surface, use 3 parts > H2O2 and 1 part NH4OH. Be careful to let the solution cool before using the > solution. Also note that the Au will react with the solution and bubble. > > Rick Morrison > Radant Mems Inc. > > > -----Original Message----- > From: mems-talk-bounces+rmorrison=radantmems.com@memsnet.org > [mailto:mems-talk-bounces+rmorrison=radantmems.com@memsnet.org]On Behalf > Of Juntao Xu > Sent: Wednesday, June 16, 2004 3:52 PM > To: mems-talk@memsnet.org > Subject: [mems-talk] Au surface cleaning > > > Hello, > > I am making chips with gold pads (10nm thick) for later AFM imaging. But I > encountered some problem. Following is my process: > > 1. Pattern gold pads on 4" silicon wafer by lift-off > 2. Coat 1um photoresist (no baking) for dicing surface protection > 3. Dice wafer into chips > 4. Clean chips by Actone/methanol/Isp/DI water to remove dicing particles > and photoresist. > 5. O2 plasma ahser descum > > The problem is: when do AFM image of gold pad, there always have a lot of > 10-15nm particles on it while the outside silicon surface is pretty smooth > and clean. I also imaged the gold surface before dicing. It is clean and no > such particles. Is it because Au surface is prone to absorb small particles > during the chip clean process, is there a way to clean them ? > > Thanks! > > Juntao > > _________________________________________________________________ > Add photos to your messages with MSN 8. Get 2 months FREE*. > http://join.msn.com/?page=features/featuredemail > > > _______________________________________________ > MEMS-talk@memsnet.org mailing list: to unsubscribe or change your list > options, visit http://mail.mems-exchange.org/mailman/listinfo/mems-talk > Hosted by the MEMS Exchange, providers of MEMS processing services. > Visit us at http://www.memsnet.org/ > > > > Wu Lei