Hi, The compounds of HMDS were created inside the process chamber. The process works by delivering HMDS vapor to a plasma field that disassociates the HMDS. It then redeposit down stream with all the differing compounds. The result is a sticky mess that can be as thick as you wish, and is hydrophobic. The only down side I know is the goop deposits every where and the interior of your chamber gets sticky. I don't know the age of the IBM patent but it is definitely over 10 years old. Let me know if I can help some more Bill Moffat. -----Original Message----- From: MM Farooqui [mailto:mmf@ecs.soton.ac.uk] Sent: Wednesday, June 05, 2002 2:58 PM To: mems-talk@memsnet.org Subject: RE: [mems-talk] SiN passivation problem Bill What are the compounds of HMDS that you deposited (which could be used on aluminium metallization) "which remained hydrophobic for ever, removeable with a simple eraser but difficult to clean" from your equipment ? Any information will be highly appreciated. regards m.farooqui > A possible answer. IBM developed a process incorporating plasma and HMDS > in the same system to deposit various compounds of HMDS. It was a thick > think many microns of sticky goop that was totally Hydrophobic. The > concept was for protection of Hybrid circuits in a submarine. The part > had to protected for ever against moisture but the material had to be > easily removable. I ran some experiments at that time combining one our > plasma systems with a HMDS delivery system. The thick goop was totally > Hydrophobic, removable with a simple eraser, but if undisturbed remained > hydrophobic for ever. Down side the equipment I was using had the goop > deposited every where and was difficult to clean. Let me Know if I can > help to find original IBM patents etc. Bill Moffat > > -----Original Message----- > From: Robert Dean [mailto:rdean@Eng.Auburn.EDU] > Sent: Wednesday, June 05, 2002 8:11 AM > To: mems-talk@memsnet.org > Subject: [mems-talk] SiN passivation problem > > > >Hello, > > I have a MEMS sensor that has aluminum traces covered with 0.4um of > silicon-nitride, for passivation, that must operate in a moist-salty > environment. The part has failed, and I suspect that the moist-salty air > has permeated through the SiN layer and damaged the aluminum traces > underneath. Any suggestions? > > > Robert Dean > > Research Associate IV > Center for Advanced Vehicle Electronics > Auburn University > 200 Broun Hall > Auburn, AL 36849 > > Voice: 334-844-1838 > Fax: 334-844-1898 > Email: rdean@eng.auburn.edu > _______________________________________________ > 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/ _______________________________________________ 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/