I am trying to alignment two layer of SU-8, but I canīt because It imposible to see the drawing of the first layer by the microscopie of mask-aligment, does somebody know wath is the problem? Is a problem with the crosslink of the first layer? or is a problem with the transparency of the second layer?
I notice that if I coat the wafer with the second layer and wait about one month, the alignment is easier.
What can I do?