Hi,

I have 8 um width,  15 um deep channels anisotropic etched in SiO2 and want
expose in a positive photoresist 3 to 6 um width lines on the bottom of
this channels. Have anybody ever tried something similar? I have problems
with optical lithography (proximity effects), so am thinking on E-Beam
lithography... Can one positioning a sample in REM without simultaneously
significant exposing the resist? There are different PMMA types (and others
resists?), what would be most suitable? Would it works at all?

Regards,
Evgeny Gutyrchik