adhesion problem for SU-8 on Si when hot-embossing
Fabrice Monti
2008-07-09
Hi,
I had a similar problem with the SU8. the problem
was the exposure time was too short. after that,
i studied the impact on the exposure time. If
your structure are under-exposed the bonding
between SI and SU8 is really bad. If your
structure are over exposed, the larger increase.
in my case, i measured the light power with a
powermeter but without the quartz plate (support
of my mask) and the mask i used. the difference is over 40% !!!
best regards,
fabrice
Le 11:50 09/07/2008,Meifang Lai écrit:
>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 â°C 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 â°C for 10min, and the demolding
>temperature is 90 â°C), 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.