Depends on the type of resist. I would not suggest boiling Aquaregia, but hot
aqua regia. Secondly, you could use polyimide as the resist. It will hold up to
the acid musch better than most resists.

Give it a try,
Chuck
_______________________________________________________________________________
Subject: Re: platinum wet etching
From:    Reid Alyn Brennen  at INTERNET
Date:    11/5/97  2:17 PM

Michael,

According to my CRC Handbook of Metal Etchants, boiling aqua regia
will remove platinum but I don't know how the resist will handle it.
(Saito, R et al - J. Electrochem Soc. 132, 224, 1985)

You could also try molten sulfur or hot sulfur vapors, also mentioned
as attacking platinum, but I wouldn't recommend it.

Good luck!

-Reid

>


>>>>>>----*----<<<<<< Start of Forwarded Message >>>>>>----*----<<<<<<
>Dear all,
>
>is there anyone, who has worked on structuring platinum with wet
>etchants? I have tried aqua-regia (3parts HCl, 1part HNO3) of 36 %,
>but could not remove any Pt from my wafers. I am using ordinary
>resist on top of the Pt for structuring.
>
>Any suggestions on aqua regia or other chemicals that could etch
>Pt are greatly appreciated.
>
>Regards,
>
>Michael
>==================================================
>| Michael Koch                                   |
>| University of Southampton                      |
>| Department of Electronics and Computer Science |
>| Southampton SO17 1BJ                           |
>| England                                        |
>|                                                |
>| Tel.: +44 (0)1703 593737                       |
>| Fax.: +44 (0)1703 593029                       |
>| email: M.Koch@soton.ac.uk                      |
>==================================================
>
>


--
.______________________________________________________________________.
|Reid (Turtle) Alyn Brennen                Hewlett-Packard Laboratories|
|rbrennen@hpl.hp.com                       Chemical Systems Department |
|(650) 857-4469 office                     3500 Deer Creek Road, MS 26U|
|(650) 852-8502 Fax                        Palo Alto, CA 94303-0867    |
`