Lou ,my advice ,stay away from wet etching if you can.
at the best it is not easy, and the  lines/pattern will look ragged.
Use the  lift of process if appicable.
regards
walter
www.elume.com
----- Original Message -----
From: "Lou Chomas" 
To: 
Sent: Thursday, May 11, 2006 5:38 PM
Subject: [mems-talk] Platinum Group Metals


> Hi All,
>     I'm trying to select a platinum group metal (Pt, Pd, Rh, Ir, Os, Ru,
> etc.) for use in my device.  I was wondering if anyone had any information
> on the etch resistance of these materials to various etches.  In
> particular, I'd like to know if they can withstand hot phosphoric acid,
> HF, BOE, and SF6 RIE.  Any help or pointers to references would be greatly
> appreciated.
>
> Best,
> Lou
>
>