SU-8 does not tend to stick to glass and quartz (and thus, SiO2) very
well at all.  Dehydration bakes and HMDS treatments seem to have little
effect.  The only thing I've found to get reliable adhesion of SU-8 on
glass, quartz, SiO2, etc. is AP 300 from Silicon Resources in Chandler,
AZ (www.siliconresources.com).

Best Regards,
Chad Brubaker

EV Group       invent * innovate * implement
Senior Process Engineer - Technology - Tel:  480.727.9635, Fax:
480.727.9700  e-mail: c.brubaker@EVGroup.com, www.EVGroup.com


-----Original Message-----
From: mems-talk-bounces@memsnet.org
[mailto:mems-talk-bounces@memsnet.org] On Behalf Of Steven Yang
Sent: Friday, January 11, 2008 2:10 AM
To: mems-talk
Subject: [mems-talk] How to improve SU-8 adhesion?

Hi, all

Asked some questions on SU-8 2050 several days ago, still stuck on it
now.

The problem is the peeling off at some SU-8 2050 microchannel
edge.(SU-8 2050 on PECVD SiO2). Without SiO2 layer, the situation will
get better with seldom cracking and peeling off. However, on PECVD
SiO2 it always turns out this problem more or less.

I have increased the temperature and time for dehrydration at 180C for
30mins. and exposured for 40s at 7mW/cm2, PEB at 65C, 95C for 5 and 15
mins respectively (Same as softbake). No much different.

If there is no any further solution based on recipe modification, will
the HMDS get the thing better? If so, could anyone give some
suggestion on the HMDS spin procedure? below is what I plan to do.
1) dehydrate at 150C for 15mins
2) spin HMDS at 7500rpm for 35s
3) dehydrate at 150C for another 15mins
4) spin SU-8 2050 at 4000rpm for 45s

Any suggestion? Thanks a lot!

Steven