One thing that I came across was the sidewall profile of the edge.
This is critical for the lift-off.

Positive resists gave out positive tone profile which might generate a
lot of troubles in lift-off. If you try to lift-off a thick film, the
deposited film could be conformal on the positive tone sidewall and
the lift-off will fail. By contrast, negative resist usually provides
a negative tone profile (you can imagine this as an undercut on the
edges). So the deposited film is naturally discontinuous on the edge.
The lift-off is easy then.

Jie

On 10/27/09, Paul Nguyen  wrote:
> Dear all:
>
>  I would like to hear your experiences of using Positive vs. Negative resists
>  in MEMS processing.   What are the PRO vs. CON?  I appreciate your
information.
>
>  Thanks and regards,
>  Paul

*  Zou Jie (Jay)
*  Department of Physics
*  University of Florida
*  Tel: +1-352-846-8018
*  Email: zoujiepku@gmail.com
*  Homepage: http://plaza.ufl.edu/zoujie/