Meifang,
        Have you tried treating the surface of the SU8 to make it slick.  A
heptadeca fluoro tri ethoxy trichloro silane can create surfaces slicker than
Teflon.  Contact me for further technical data.  Bill Moffat


-----Original Message-----
From: mems-talk-bounces@memsnet.org [mailto:mems-talk-bounces@memsnet.org] On
Behalf Of Meifang Lai
Sent: Wednesday, July 09, 2008 2:51 AM
To: 'General MEMS discussion'
Subject: [mems-talk] adhesion problem for SU-8 on Si when hot-embossing

Hi all,

I am developing a mold for hot-embossing by using SU-8 2050 on Si wafer. At
present, I can get beautiful structures on Si after the photolithography process
(including hard bake at 150 ⁰C for 30 min). However, when I was trying to
transfer the structure to PMMA (1 inch square) by hot embossing (pressure is 300
Kg, 125 ⁰C for 10min, and the demolding temperature is 90 ⁰C), all the Su-8
structures stayed in PMMA and separated from Si wafer. I have tried the HMDS,
but it seems no difference. Does anyone have similar experience? Any suggestion
will be appreciated.