Thanks for the help David. Unfortunately, it still doesn't seem to work.
I tried hot(85'C) un-diluted aqua regia (3 parts HCL, 1 part HNO3) for
as long as 30mins and I had only 15nm of Ir and still there was no
etching.
I also tried another recipe (1part HNO3 + 5 part H2O + 10part HCl at
85'C) but didn't get any results.

Does anyone have any experience in wet etching Iridium? Any pointers
would be highly appreciated.

Regards,
Manu


-----Original Message-----
From: [email protected]
[mailto:[email protected]] On Behalf Of David Nemeth
Sent: 29 January 2007 09:12 PM
To: 'General MEMS discussion'
Subject: RE: [mems-talk] wet etch recipe for Iridium (Ir)

According to the Handbook of Metal Etchants (isbn 0-8493-3623-6,
EXCELLENT resource), hot aqua regia (3 parts HCL, 1 part HNO3) non
diluted is the only wet etchant for iridium known.  They mention it
etches very slowly.

David Nemeth