Using a bi-resist to get an undercut will probably work the best.

I have used Shipley 1805 on top of Microchem's LOR 3B.  I can easily lift
off up to about 250nm.  You can get the LOR in different thicknesses for
thicker metal films.
Some of my coworkers have used a PMMA bi-layer recipe that they like, but
you need a deep UV blanket exposure.
e-mail me if you are interested in either of these processes.

Glen
landry@anvil.nrl.navy.mil

At 12:01 PM 12/4/2003, you wrote:
>Dear All,
>
>does anybody has experience in a metal-lift-off-process? I am searching for
>a resist working fine for soft metal with a thickness of about 300nm. May be
>you can advise me either negative or positive resists.
>
>I would appreciate any help,
>Thanks in advance,
>
>Bernd Krueger