Connie, Most likely you have a wafer that was slightly offcut from the <110> plane which would result in angled channels. Where did you get your wafers? What was the tolerance on the <110> specification? Many vendors are unable to maintain tight tolerances. Andrew J. Nielson -----Original Message----- From: Connie Kathleen Smith [mailto:cksmith@ruf.rice.edu] Sent: Monday, January 07, 2002 8:41 AM To: 'mems-talk@memsnet.org' Subject: RE: [mems-talk] 110 Si etching with 20%KOH From literature and others' suggestions I was led to believe that to get vertical walls I would have to use 110 Si wafers. The channel I am etching is only about 200um wide and 500um deep. Connie Smith Rice University On Mon, 7 Jan 2002, Knighton, Ed wrote: > Hi Connie, If you switch to <100> Si Wafers Your problem will go away. > > Ed Knighton, Process Engineer > Constellation Technology Corp. > > > -----Original Message----- > > From: Connie Kathleen Smith [SMTP:cksmith@ruf.rice.edu] > > Sent: Friday, January 04, 2002 1:40 PM > > To: mems-talk@memsnet.org > > Subject: [mems-talk] 110 Si etching with 20%KOH > > > > I am trying to fabricate a flow channel with vertical side walls using a > > <110> Si wafer. When I etch all the way through the wafer (which is > > desired) the side walls are slanted. The wafers are coated with SiO2 and > > Si3N4 as protective barriers during etching. I expected to lose several > > microns vertically during etching but the slanted walls were unexpected. > > > > Thank you, > > Connie Smith > > Rice University > > Department of Chemical Engineering > > 6100 Main MS 362 > > Houston, TX 77005 > > _______________________________________________ > > 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.mems-exchange.org/ > _______________________________________________ > 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.mems-exchange.org/ _______________________________________________ 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.mems-exchange.org/