hi friends
i have etched si wafer for 30 um using KOH. the cavities are of size 1000 X
2000 um.
but when i am doing lithography on this surface, the photoresist is not
covering all the  area, specially from top side of top surface.
i have tried with thicker photoresist (at 2000 RPM), but it is not working.
i am using HNR120 (-ve PR) and S1813 (+ve PR)
please suggest me to solve this problem.
-abhay joshi
Reserch student,
university of pune,
India