Chiro:

I wouldn't try hot phosphoric as the photoresist will lift almost immediately.
RIE is the proper way to etch the nitride film so if you would like some help
with a receipe send along what process conditions and etch tool you are
currently using and I will try to help you. Bob Henderson

-----Original Message-----
From: gupta_pramod@yahoo.com
To: mems-talk@memsnet.org
Sent: Thu, 12 Apr 2007 11:07 PM
Subject: Re: [mems-talk] Re: silicon rich nitride wet etch


Try Phosphoric acid @ 155C used for etching of LPCVD, i.e. silicon rich SiN film
in Semiconductor/MEMS industry. For process details, open the Stanford Nano
Fabrication (SNF) Process link as follows;

  http://www-snf.stanford.edu/Equipment/wbgeneral/NitrideEtchWBGen.html


Ciro Chiappini  wrote:

I have to etch a 2000A thick silicon rich nitride film under a
photoresist (AZ5209) mask. I need to get a nitride mask since the next
step is electrochemical etching in EToH:HF 3:7. I am currently RIE
etching it, but the process is very time consuming.

I tried wet etch both HF:H2O 1:10 AND HF:HCL 1:1 but the resist gets
peeled off in few minutes.

Do you have any alternative recipe to suggest?