[mems-talk] Nit and Oxide etching.

[bobhendu at aol.com]

I know of no rie type process that will give you the selectivity numbers you are requesting even low pressure chlorine type etching of nitride I don't think will give those results. Only hot phosphoric acid in a reflux bath can obtain those selectivity numbers and you can't use photoresist as a pattern since it will go away. Bob Henderson 
 
-----Original Message-----
From: iamacalbear at hotmail.com
To: mems-talk at memsnet.org
Sent: Wed, 25 Apr 2007 11:29 AM
Subject: [mems-talk] Nit and Oxide etching.


hello, 
 
I am trying to find a way to etch Nit faster than silicon oxide layer (under the same conditions). 
I am hoping get 50:1 type of etching ratio (more nitride removal than the oxide layer). We have tried a couple of things but nothing has really panned out...any suggestions? 
 
Mike