Hi Ren,

thanks for the information
just one thing, between exposuring of the first layer and depositing of the
second layer,
is it necessary to do a post-expose bake?
cos I think the first layer su-8 will be over-crosslinked if the postexpose
bake is performed.
on the other hand, a post-exposure bake must be performed immediately after
exposering, according the datasheets.

thanks

chenhan lee

-----Original Message-----
From: mems-talk-bounces@memsnet.org
[mailto:mems-talk-bounces@memsnet.org]On Behalf Of Ren Yang
Sent: 11 August 2005 17:39
To: General MEMS discussion
Subject: Re: [mems-talk] multi-layer SU-8


Hi Lee,

You can expose the first layer SU-8 first. Then
deposite a layer Cr/Au, and coat the second layer
SU-8. Pattern the second layer SU-8, the UV light will
not go through the metal layer. Develop the second
layer SU-8, etch metal layer, then develop the second
layer SU-8 to get what you want.

There is a paper. It may be helpful: ~{!0~}Fabrication
of microscale two-level surface-engineered mold
inserts for MEMS applications by UV-LiGA and conformal
coating deposition~{!1~}, Photonics West, Jan 2005 San
Jose, CA, Proceedings of SPIE Vol.5717,  [5717-24],
p175-184