Hi Matthieu,
I used e-beam evaporation. Under microscope I can see double lines of edges.
Although I did not check the profile of structure, I think it should imply an
undercut profile. My evaporation stage was tilted to cover some side walls of
tall structures. What I found was I can remove the metal by using sonicator. I
think actually the metal was lifted but just still adsorbed on the surface of
structures. I do not prefer sonicator as it damaged my SU-8 structures. Is there
anything that I could try to dissolve the negative resist for lift off while the
lifted metal would not be re-adsorbed to the surface?
Cheers