Try Transetch-N at http://www.transene.com/al2o3.html.  It purports to etch
SiNx but not SiO2.  It is (I believe) a concentrated Phosphoric Acid
solution that you should operate at 180 deg. C.  I don't know if just
Phosphoric Acid will work, but you might look it up.

HF or Buffered Oxide Etch should etch both SiNx and SiO2, though I am unsure
as to the relative etch rates.

-Bill

-----Original Message-----
From: [email protected]
[mailto:[email protected]]On Behalf Of [email protected]
Sent: Friday, October 08, 2004 12:34 PM
To: General MEMS discussion
Subject: [mems-talk] Ask about tchant for Si3N4


Hi,
I need an etchant that can etch Si3N4 but not SiO2.
Anybody can suggest anything?

And also:
Do you know any etchant which can etch both SI3N4 and SiO2?

I need both processes,

Thanks all,
Laleh


Laleh Rabieirad
PhD Student
ECE Department
Purdue University
_______________________________________________
[email protected] 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/