Wet etching platinum is not a good idea for the reasons that you are
experiencing.

May I suggest a lift of process, it works well it will solve your problem.

engineering@elume.com

----- Original Message -----
From: "abhaya joshi" 
To: 
Sent: Saturday, August 08, 2009 7:25 AM
Subject: [mems-talk] about platinum etching


> hi,
>
> i am doing platinum etching (200nm). i am using HCL (8):HNO3 (1) solution
> at
> 70C>
>
> i am observing lot of non uniform etching behavior and lot of
> undercutting.
> can any one suggest how to avoid this.
>
> -abhay joshi
> university of pune
>
>