Manu,
  Perhaps your best bet is to give up on etching and try a liftoff, if that
works with you process.  Or use an ion mill.  Some things are too hard to
etch chemically.

David Nemeth

-----Original Message-----
From: [email protected] [mailto:[email protected]]
On Behalf Of Mantavya Sinha
Sent: Tuesday, February 20, 2007 10:48 PM
To: General MEMS discussion
Subject: RE: [mems-talk] wet etch recipe for Iridium (Ir)

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