Hallo Nan Sie

I had the same problem and my answer was in the exposure time. which
source you are using and how long do you expose?

Dr Laetitia Philippe
Electrochemistry and Micro-patterning Group
EMPA

>>> [email protected] 04/20 2:44 am >>>

I am developing SU-8 2050 after spun around 50um.
My procedures for soft baking, exposure, and PEB are correct.
I am having trouble getting clean develops after about 6min and 2-3s
acetone spray.
What I am getting are some milky residue around my features. I
understand I need to develop it more when this occurs, but this milky
residue still remains or the SU-8 would come off.

Anyone have any suggestions? Maybe I need to expose more?