Hello,
It is hard to say the reason why you have poor pattern, as you did not
mention about the protocol. Have you used the right UV exposure? Check
it first. It is also important to check the lift off process, I think
you are facing problem because of wrong lift off process, (high
concentrated developer with extreme time). Have you used and additional
layer as adhesion layer? Cr provides good result. It is also important
to know on what substrate you are having this problem, is it glass/Sio2
or polymer? Accordingly, you have to follow the lift off process.
Say to more about your problem solution need to know more.
Thanks.
Mamun

***************************************************************
Mamun-Ur-Rashid
PhD Candidate
Orion 1.12
Centre for Nano and Microsystem
School of Science & Technology
University of Teesside.
TS1 3BA. U.K.
01642342428
www.mamun.info

-----Original Message-----
From: mems-talk-bounces@memsnet.org
[mailto:mems-talk-bounces@memsnet.org] On Behalf Of
yitianp@email.arizona.edu
Sent: 09 March 2007 22:30
To: General MEMS discussion
Subject: [mems-talk] lift-off

I have lift-off the gold on photoresist.
But some part of the pattern is very clear,but other area is not.
What reason can cause the phenomena?