Xiaoyong,

         This is a maybe cure.  If you use image reversal to create a
reverse profile for lift off you can use thicker resist and not need to
bake as long.  It may make the process more acceptable.  I can offer
free tests of the process if it is a possible way to go.

Bill Moffat, CEO
Yield Engineering Systems, Inc.
203-A Lawrence Drive, Livermore, CA  94551-5152
(925) 373-8353

www.yieldengineering.com


-----Original Message-----
From: mems-talk-bounces+bmoffat=yieldengineering.com@memsnet.org
[mailto:mems-talk-bounces+bmoffat=yieldengineering.com@memsnet.org] On
Behalf Of Xiaoyong Liu
Sent: Wednesday, July 21, 2010 11:39 AM
To: mems-talk@memsnet.org
Subject: [mems-talk] direct patterning/fabrication on existing SiN
membrane

Hi,
   I am in the process of fabrication of some patterning  on SiN
membrane window. It involves of lithography, film deposition and
liftoff. Since membrane is so fragile(the thickness is about less or
around 100nm), it is very easy to break during lift off/ cleaning
process which may require sonication, some times even N2 blow dry may
damage membrane window.  I am wondering if anyone have experience of how
to handle it and share it with me.

Thanks

Xiaoyong