=20 ciao andrea. we use a fuji film negative resist sc 450 (original - hunt, waycoat olin)=20 and it can hold out for about 8 minutes in a 2:1:1 ratio at a very low temperature.=20 avi Date: Sun, 28 Oct 2007 15:14:17 +0100 (CET) From: "Andrea Mazzolari"Subject: [mems-talk] HNA resistant photoresist Hi all, i'm looking for a photoresist which will be resistant to HNA etch. My HNA composition is HF: 2 parts, HNO3: 15 parts, CH3COOH: 5 parts. Etch time is 200 minutes. So this photoresist must be resistant for a long time. Can someone suggest a photoresist ? I have already tried S1813, but after about 3 minutes etch it peeled off.