hi andrea,

kirt williams already gave the answer, but here is also my recommendation,
how i did it last times. do you want to etch slow or fast? in any case you
need an HF-based etchant...there is no other way...

=> try e.g. AF91, which is a 10% buffered HF-solution with a wet etch-rate
of about 60nm/min in case of SiO2, or use simply a 1%HF-solution (ca.
6nm/min).


please give some feedback about the results.


cheers,
michael


> -----Ursprüngliche Nachricht-----
> Von: [email protected]
> [mailto:[email protected]] Im Auftrag von Andrea Mazzolari
> Gesendet: Mittwoch, 29. November 2006 18:05
> An: 'General MEMS discussion'
> Betreff: [mems-talk] Silicon oxide etch
>
> Hi all,
> I need to etch silicon oxide using a silicon nitride mask.
> Any suggestion
> about a wet etchant which will etch only silicon oxide
> preserving silicon
> nitride?