Hi Sreemanth, If you don't find a cleaning solution that works, I could possibly repolish it depending on the amount of material that can be removed. Warm regards, Julie Mark Optics -----Original Message----- From: mems-talk-bounces@memsnet.org [mailto:mems-talk-bounces@memsnet.org] On Behalf Of Sreemanth M Uppuluri Sent: Tuesday, May 29, 2007 7:23 PM To: mems-talk@memsnet.org Subject: [mems-talk] Fused Quartz Cleaning Hello All, Thank you all very much for the replies I got for my previous queries. I have another one now ;-) I am trying to clean fused quartz wafers that have been used as substrates several times for coating photoresist (Shipley S-1800 series). I have tried solvent clean (Acetone & Methanol) and even Piranha (1:1) but still I see that the surface has some traces of photoresist on it. I would like to know the best procedure for removing organic and metallic contaminants (Cr,Al) from fused quartz wafers without affecting the wafer itself. Please let me know if you have any suggestions.