Hello Mark, Chromium forms a volatile oxide at higher temperatures (>=~190°C). Therefore you should keep the wafer temperature low by either cooling from the backside, or running a pulsed plasma, or ashing in several shorter runs, or.... Unfortunately I do not know your etch equipment but if it is not really necessary to have 25W on the platen I would decrease it to a minimum. My wild guess would be that not only the temperature impact would be much lower without it and also the physical. Maybe you should increase O2 flow and higher coil power a little instead. Best regards, Martin Lapisa Microsystem Technology Laboratory School of Electrical Engineering Royal Institute of Technology (KTH Stockholm) -----Original Message----- From: Curtis, Mark E. [mailto:Mark.E.Curtis-1@ou.edu] Sent: Mittwoch, 16. Januar 2008 16:45 To: mems-talk@memsnet.org Subject: [mems-talk] RIE removal of S1818 photoresist Hello all, Im using Shipley S1818 positive photoresist as a mask for wet-etching a 100 nm thick film of chromium. After using a wet chemical photoresist stripper there remains some photoresist residue on the surface of the chromium. Ive attempt to use a Trion RIE to remove the photoresist residue with the following etch parameters: Gases/Flow Rate (O2/50 sccm), Pressure (500 mTorr), RIE Power (25 W), ICP Power (500 W), and Time (30 min). To my surprise, I found that not only did it remove the photoresist but also the chromium. Does anyone know of a good photoresist removal recipe for RIE that will not etch chromium. I have previously tried a shorter etch time (~10 min) but it did not completely remove the photoresist residue.