HI Fellows, BTW: you are using glass, could the diffraction and reflection effect be stronger and cause surrounding SU-8 cross-linked? possibly... can you try the process with a Si and compare? thanks. zeta yu yul.fany@gmail.com wrote: >Thanks for the reply. As you expected, the hotplate and exposure lamp >are always on. I did change developer after each trial and clean the >beaker by rinsing with developer. Is it possible there is still some >trace solvent (say cyclopentanone, the solvent for su 8, or water >vapor) remaining in the developer? >But I just blowed dust off the coverglass with nitrogen without >cleaning it with, for example, IPA. I guess it is related to the >adhesion between coverglass and su 8, but not sure which step in the >protocol determines this. > >Best, >Liu Yu >