Hi, There could be several mechanisms that cause permanent stiction of working device. These depend on the operation procedure and packaging. I encountered several of the following problems: 1) If you have dielectric layer than charging may cause that. 2) If you don't use vaccum or dry N2 encapsulation than you may still have problem with high humidity that may cause stiction, similar to what happen on the wet rlease process. 3) Depending on the stiffness of your device you may encounter the Casimir effect that is known to cause stiction for devices with low stiffness 4) I also encountered problem with short circuiting of electrode that caused fusion of the electrodes. 5) small dust particles between the electrode may also burn due to short circuiting and cause stiction To avoid most of the above I never use dielectric coating, use vacuum encapsulation and the most important is using landing electrodes that have the same potential as the actuator and don't short circuit the electrodes. This way I manage to run the device for milions of cycles without any problems. Hope this will be helpful for you SHALOM Ofir -----Original Message----- From: mems-talk-admin@memsnet.org [mailto:mems-talk-admin@memsnet.org]On Behalf Of Fende, John R. Sent: Wednesday, October 16, 2002 3:33 PM To: mems-talk@memsnet.org Subject: RE: [mems-talk] Re: stiction of contacting surfaces It seems Wenlin is talking about stiction occuring after fabrication, where van der waals and surface tension are out of the picture. Do you have any knowledge of causes of stiction after a working device is activated several times? John Fende > -----Original Message----- > From: J [SMTP:jhwen@ycity.com.tw] > Sent: Thursday, October 10, 2002 5:57 PM > To: mems-talk@memsnet.org > Subject: [mems-talk] Re: stiction of contacting surfaces > > Dear Wenlin, > mainly the stiction comes from dry process. water capillary force may draw > beam towards substrate and other forces like van der waals or surface > tension developed. > the solutions might be heat up when you dry it, or use solution such as > IPA to lower the surface tension, XeF2 or CO2 for supercritical > sublimation, or simply modify your layout structures for anti stiction. > good luck. > > Inst. of MEMS, NTHU > > > Message: 8 > To: mems-talk@memsnet.org > From: Wenlin.Jin@jdsu.com > Date: Thu, 10 Oct 2002 09:58:02 -0400 > Subject: [mems-talk] stiction of contacting surfaces > Reply-To: mems-talk@memsnet.org > > Hello: > > I'm working on electrostatic curved beams. It has been observed that > after certain cycles of operation, stiction of the beam to substrate > occurs. I'm wondering if there are researches done on the mechanism of the > stiction and how it can be avoided. Any information will be appreciated. > > Best regard > > Wenlin Jin > > > > _______________________________________________ > 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/ _______________________________________________ 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/