Hi Thomas You could try AZ9260 or 4260. I've had good experience with AZ9260. With a high selectivity DRIE recipe I've been able to do etch as deep as 1300um. Best Leo On Tue, Mar 31, 2009 at 1:29 PM, Thomas W Friskwrote: > Dear All, > > I need to pattern fairly large features (10s of micrometers) with a thick (? 5-10 µm) positive photoresist. It should withstand some fairly tough etching (DRIE, through wafer, fast'n hot production machine). Last time I did such (say 7 years ago) we used 5470 (or was it 5740?). I seem to remember this was not working out so well. > > Now, what is the name of the game today? On our shelves I've found SPR 220 4.5 and AZ 4533. Could these be useful? And heard of AZ 9060 something..... Or should I get something even newer? > > All opinions welcome, such as ease of use, tedious protocol, weird baking procedures, multi-exposure, PEB, developer issues or? > > Brgds Thomas F > Post-doc -- Xiaoguang "Leo" Liu Birck Nanotechnology Center, Purdue University, 1205 W.State Street, West Lafayette, IN, 47906 USA liu79@purdue.edu