Hi, friends

In bulk microfabrication, I tried to fill a deep channel, which is around
200um. When I use AZ5214, there are lots of air bubbles coming out when I
bake it. So how can I solve this problem?
Do I need to use different PR? High thick PR?
I want to try SU-8, but my friends told me that is a dirty material and
not easy to remove after baking.
Thanks a lot
Hongyu