Silicon nitride works better with KOH, you should find the etch rate is
lower for oxide if you use TMAH.

-----Original Message-----
From: [email protected]
[mailto:[email protected]] On Behalf Of Ruiz,
Marcos Daniel (SGNCOE)
Sent: Monday, February 13, 2012 12:40 PM
To: General MEMS discussion
Subject: Re: [mems-talk] Sputtered oxide as KOH anisotropic wet etching mask

Assuming sputtered oxide will have the stoichiometry that will be resistant
to the etch; the main problem I see is that sputtered films tend to be
porous.  Annealing might help, but I suspect sputtering will result in a
poor mask material.

Dan