Transene makes a chrome etchant called CR-14.
It is used for the definition of high precision
photomasks.

It does not attack photoresist (SC 1800 series)
or SiO2.  The etch rate is approximately 750
angstroms per minute.  If I can recall correctly,
the etchant is mainly composed of nitric acid.

They also make all different kinds of etchants for
several different thin films, ranging from metals
such as titanium, gold, and aluminum to dielectrics
such as oxide and nitride.

Their contact information is:

        Transene Co. Inc.
        10 Electronics Ave.
        Danvers, MA 01923
        Tel: (978) 777-7860
        Fax: (978) 739-5640

P.S. I think they may also be on the web.


-----Original Message-----
From: David Menche [mailto:dmenche@lightwavemicro.com]
Sent: Monday, May 10, 1999 2:35 PM
To: MEMS@ISI.EDU
Subject: Chrome etch



  We are using chrome as a hard mask to dry etch SiO2.
What is a good chrome echant that will not attack the photo resist, nor
SiO2, and what kind of etch rate is expected.   tried potassium
permaginate/potassium hudroxide solution, and find it is very slow at
chrome etch, and fast at dissolving the resist.

thanks    dave menche