Hello All.

              I am working on 2 level SU-8 lithography now. The first
layer is about 50um thick and have a feature size of 50um; the second
layer is 10-20um thickness, the feature size is about 25um.

              I need suggestions right now. Should I develop both layers
at once after PEB of second layer, or can I develop the first layer and
spin on the second?

              Also is there any particular precautions I should take in
2 level SU-8 lithography?

              I also appreciate if someone can suggest related
literatures.

best,
Leidong Mao