Are you using evaporation for the metal deposition? What type of metal
deposition equipment are you using. If not using evaporation for metal
deposition set parameters for poor step coverage which would be to have
the substrate cold for starters. However, given you are attempting lift
off I am assuming the substrate is unheated already.

Also, what is the height of the bi-layer relative to the metal
thickness?

Edward H. Sebesta
Independent Process Engineer

-----Original Message-----
From: mems-talk-bounces@memsnet.org
[mailto:mems-talk-bounces@memsnet.org] On Behalf Of James Paul Grant
Sent: Thursday, January 15, 2009 10:35 AM
To: General MEMS discussion
Subject: [mems-talk] Lifting-Off 1um metal


Hello.

A colleague of mine is having a lot of difficulty lifting-off 1um of Al
deposited on a pattern written in a bi-layer of e-beam resist (thickness

1.3 um) that has a minimum feature size of 1 um.

Essentially lift-off is a total failure (he has had the sample in 45oC
acetone for over 2 days).

He has used the standard bi-layer process with PMMA resist to achieve an

overhang profile to aid lift-off.

Any advice would be much appreciated.

Dr. James Paul Grant