Hello Qinghong, there are two very good bilayer materials that I have
used.  The first is ProLIFT from Brewer Science, and the second is LOR
from MicroChem.  The LOR is formulated in two varieties for MIF and MIB
developers.  You can also use AZ's NLOF which is a single layer
negative-toned lift off resist.  All three should give you good results
and clean lift-offs.  I am assuming that the geometry you are printing
is pretty large.  If it is small I would recommend the LOR for sure.

Hope this helps.

Best Regards,
Dustin Warren

EV Group
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Application Engineer - Direct: +1 (480) 305 2447, Main: +1 (480) 305
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-----Original Message-----
From: Qinghong Du [mailto:[email protected]]
Sent: Monday, February 09, 2009 11:47 AM
To: General MEMS discussion
Subject: [mems-talk] Bilayer PR for 2um Au lift-off process

Hi

I am looking for bilayer PR lithography to generate undercut for 2um Au
lift-off process. Anyone can sugguest some solutions? Currently I use
OCG825 and AZ5214E bilayer PR, but it is not very stable.

Thank you for your help.

Qinghong
DiCon Fiberoptics, Inc.