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.