Hello, everyone,

I met a problem in SU-8 process recently, the SU-8 layer stick to the mask
after exposure.
I rarely have this problem before. Two weeks ago, I applied an Omega UV
filter for the exposure step to filter out short wavelength UV light.
And this problem appear every time during exposure.
At first I think it may be caused by insufficient soft-bake dose, but after
I tried to prolong the baking time and use higher temperature, SU-8 layer
still sticked to the mask.
Does anyone have some ideas about this problem? Please help me out.

By the way, the photoresist is SU-8 2150 by microchem, will be expired at
Dec,2008.

Thanks!
--
Best Regards,

郑瑞麟

Ruilin Zheng

Address:
Pen-Tung Sah MEMS Research Center,
Xiamen University, Xiamen,361005,
P.R.China