Arthur, One method to build up KOH resistance is to perform an edge protection coat. With this method, resist is dispensed only at the edge of the wafer, with the specific intent of preventing etching. We've even developed a system that will follow the flat of the wafer to ensure an even distribution of resist around the entire edge. Use of a following proximity bake will allow proper cure for excellent etch resistance (so that your wafer doesn't come out looking like something that had been nibbled by a mouse). 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@memsnet.org [mailto:mems-talk-bounces@memsnet.org] On Behalf Of arthur beyder Sent: Sunday, July 18, 2004 11:19 AM To: mems-talk@memsnet.org Subject: [mems-talk] KOH wafer edge protection for long etches I would like to protect the edges of my wafers during long KOH etches (8-10hrs, 500um deep). I am etching my wafers on both sides, thus I can't spin on protective layers (such as ProTec or BPR100). Does anyone know whether I can paint these on and then bake the wafers to cure? Are there any other approaches for KOH protection? Thank you, Arthur Beyder _______________________________________________ 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/