Andrea,
If the cantilever base is does not have a diameter ~10 times or more than
the nitride thickness they will lift off. Id the base is large enough, and
oxide will remain at the center.
shay

-----Original Message-----
From: mems-talk-bounces@memsnet.org [mailto:mems-talk-bounces@memsnet.org]
On Behalf Of Andrea Mazzolari
Sent: Friday, December 08, 2006 11:45 PM
To: General MEMS discussion
Subject: Re: [mems-talk] silicon nitride bridges and cantilevers

It is LPCVD silicon nitride. Thickness is 70nm.
Under silicon nitide there are 20nm of LPCVD silicon dioxide.
Silicon dioxide is etched by KOH, right ? And so the underlying silicon
dioxide layer was removed. Maybe this is the cause i've lost cantilevers and
bridges ?