There could be a few different reasons for lift off of your patterns during develop: 1: The initial adhesion to your substrate is poor. In this case, ensure that you are performing a dehydration bake (150(C, 1-2 minutes on a hot plate) prior to coating. If you are doing this already, then you may want to contact Silicon Resources (at siliconresources.com) for a supply of their AP300, which has been shown to enhance adhesion with SU-8. 2: You are underexposing your film. Bare in mind, you are patterning a negative material on a transparent substrate. You are not getting the radiation reflection that you could expect from a silicon substrate, so the standard recommended dose may not be sufficient. With a negative material, if your dose is insufficient, you may not get crosslinking at the bottom layers of the material (especially with SU-8, where the photoactive compounds will not diffuse and migrate within the film after activation). If the material is not crosslinked, it will actually develop out (dissolve) in the developer solution, causing liftoff. 3: Your post-exposure bake is not correct. The recommended post exposure bake is with a hotplate. Due to the thickness of many SU-8 films, heat transfer in an oven environment may hamper the curing of the portion of resist closest to the wafer. The material may remain under-crosslinked, and again dissolve in the developer. Best Regards, Chad Brubaker EV Group invent * innovate * implement Technology - Tel: (602) 437-9492, Fax: (602)437-9435 e-mail: C.Brubaker@EVGroup.com, www.EVGroup.com This message and any attachments contain confidential or privileged information, which is intended for the named addressee(s) only. If you have received it in error, please notify the sender immediately and then delete this e-mail. Please note that unauthorized review, copying, disclosing, distributing or otherwise making use of the information is strictly prohibited. -----Original Message----- From: mems-talk-bounces+c.brubaker=evgroup.com@memsnet.org [mailto:mems-talk- bounces+c.brubaker=evgroup.com@memsnet.org] On Behalf Of annuar Sent: Monday, June 14, 2004 5:55 PM To: mems-talk@memsnet.org Subject: [mems-talk] SU-8 adhesion to glass substrate Hi everyone. I'm having problem coating my glass slide with SU-8 resist. It seems that the SU-8 does not adhere very well to glass. After developing, some part of my patterns are lifted off. Does anyone know how to solve this problem? Does the softbake or PEB have anything to do with this? Thanks. Abang Annuar _______________________________________________ MEMS-talk@memsnet.org mailing list: to unsubscribe or change your list options, visit http://mail.mems-exchange.org/mailman/listinfo/mems-talk Hosted by the MEMS Exchange, providers of MEMS processing services. Visit us at http://www.memsnet.org/