Hi mems-talk members,

I need some advice.
I am trying to fabricate a two-layer SU-8 structures.
the bottom layer has 15um holes and the top layer has 5um holes.
the problem is that becuase SU-8 is a negative resist, if the structure is
done from normal two layer process, the bottom will have 5um holes as the
top layer.
when exposing the top layer, UV light will penetrate through the top and
exposing the bottom one too.

could anyone help me with these obstacles?
any suggestions are helpful

thanks

chenhan