Richard, Argon is inert, Argon plasma is electrically active but still inert. It can sputter but the amount removed is small. Think maybe an Angstrom a minute in a low energy hybrid plasma descummer, maybe 10 Angstroms a minute in a high intensity single wafer resist stripper. With an over $1M Applied Materials 5000 R.I.E. think maybe 100 Angstroms per minute. All of which is cost and time prohibitive. Think metal lift off for definition better than 0.08 micron thicknesses up to 20 to 30 Microns of copper. 10 Microns of Tantalum for flip chip bumps or well over 5 microns of Gold. Contact me for more details. Bill Moffat, CEO Yield Engineering Systems, Inc. 2185 Oakland Rd., San Jose, CA 95131 (408) 954-8353 -----Original Message----- From: mems-talk-bounces@memsnet.org [mailto:mems-talk-bounces@memsnet.org] On Behalf Of Richard Chang Sent: Tuesday, December 06, 2005 4:07 PM To: General MEMS discussion Subject: [mems-talk] Argon plasma for gold etching Hi, All, I want to use argon plasma to etch away exposed gold. My thickness of gold is 1 micron. Does anybody have the recipe for the plasma etching, like RF power, pressure of Argon? How long it might take to etch away 1 micron thick gold?