Hello all,
I need to find undercut when a photoresist is developed using a certain
developer. I was planning to do lithography on a glass wafer and check for
the undercut from backside. I was wondering how significantly the exposure
times would vary. My actual product is on silicon and am not sure if its
safe to assume that the undercut on glass wafer be treated as undercut on my
silicon wafer?? I am positive that the undercut has to do mainly with the
developer and photoresist chemistry but am not sure to what extent exposure
affects it.

Does anyone has experience determining the undercut easily when you have the
patterns close to 50um thick and is difficult to focus the bottom using
optical microscope.

Regards,

Pavan Samudrala