Ahmad, I have used Shipley 1805 for years and always got bad results if the primer step wasn't done properly. While it might work for your particular process, without primer the process window is very small and I would suspect you'd have under-etch and/or washout issues. I'd run some experiments and see; if you do, do tell us the results! Regards, Robert Bock -----Original Message----- From: mems-talk-bounces+mastering=dvdfactoryinc.com@memsnet.org [mailto:mems-talk-bounces+mastering=dvdfactoryinc.com@memsnet.org] On Behalf Of Haider, Ahmad M Sent: Monday, January 13, 2014 12:17 PM To: mems-talk@memsnet.org Subject: [mems-talk] Shipley 1827 resist without hmds or p20 primer Hi, I am using Shipley 1827 resist for photolithography. Till now, I always have a pre step in which I spin p20 primer onto the wafer and then I spin the 1827 resist onto the wafer. I am facing certain problems with this. Can I just spin 1827 on a clean wafer directly? Can I get some help with the process parameters? Thanks Ahmad _______________________________________________ Hosted by the MEMS and Nanotechnology Exchange, the country's leading provider of MEMS and Nanotechnology design and fabrication services. Visit us at http://www.mems-exchange.org Want to advertise to this community? See http://www.memsnet.org To unsubscribe: http://mail.mems-exchange.org/mailman/listinfo/mems-talk _______________________________________________ Hosted by the MEMS and Nanotechnology Exchange, the country's leading provider of MEMS and Nanotechnology design and fabrication services. Visit us at http://www.mems-exchange.org Want to advertise to this community? See http://www.memsnet.org To unsubscribe: http://mail.mems-exchange.org/mailman/listinfo/mems-talk