Hi,
We are currently trying to do Ebeam lithography on metallic layers (about
10 nm thick). We use PMMA resist and 30 keV electron energy. Whereas we
obtain good results with silicon substrates (18-30 ohm.cm), the patterns
are dramatically rounded on glass substrates. Can it be du to a dramatic
proximity effect on glass? We rather suspect that some charges are trapped
in the substrate despite the conductive metallic layer between the
substrate and the resist. Does some of you have any experience with Ebeam
lithography on glass or insulator substrates or can advise any reference on
that subject?
Regards
Francois