Maggie,
       I am pleased you are using Gelest, their Silane catalogue is super
helpful.  They also have in house experts that can help you with questions about
the reaction of their chemicals.  Your problem is with the method used to get
the silane reaction.  The most important part is to have no moisture or Oxygen
present when the reaction starts.  With the silane in a separate heated
container put the substrate in a heated vacuum oven.  Then pull a series of
vacuum/hot Nitrogen purges.  At a vacuum of 10 Torr water boils at 11 degrees C
so total dehydration is a simple matter of multiple purges and sufficient
vacuum.  We use 3 purges then a vacuum of 1 Torr.  At 1 Torr water boils at -20
degrees C, so total dehydration.  Also with multiple vacuum/Nitrogen purges you
remove all the Oxygen.  Now open a valve between the warm silane and the process
chamber.  The result is the warm silane vapor sees no moisture, no Oxygen and
reacts with the Hydroxyl ions on your substrate with perfect adhesion, and
perfect contact angle for releasing layers.  Contact me for multiple technical
papers on the subject.  Bill Moffat

-----Original Message-----
From: mems-talk-bounces+bmoffat=yieldengineering.com@memsnet.org [mailto:mems-
talk-bounces+bmoffat=yieldengineering.com@memsnet.org] On Behalf Of Shao
Guocheng
Sent: Wednesday, June 30, 2010 7:12 PM
To: qlai@ucla.edu; General MEMS discussion
Subject: Re: [mems-talk] releasing layer for PDMS mold

Hi Maggie,

Those silane you used should give you good result. The ideal process should be:
vacuum the chamber where you put ur mold in; then introduce saline vapor into
that chamber; then close all the inlet and outlet to treat the mold for 30min;
then vacuum the chamber again, may use N2 to flush out the residual silane.
after this process, you should get a good non-sticking mold.    However, there's
an easy way. I used to use HMDS (safer than those u used) in a dissicator and it
worked fine for me. Just pour some HMDS in a glass vial, put the vial and ur
mold into a dissicator, pump it down (not too much, i only used our facility
vacuum line, a mechanical pump should be good enough), close the outlet to
create a HMDS vapor environment for ur mold. let it there for 2 hrs. Open the
dissicator and u should be good to go. you can try to put a small water droplet
onto ur mold and see how the treatment has changed its contact angle.   Good
Luck.
 and be careful with those silane.

Guocheng Shao