Dear Peter, The problems are probably due to internal reflections in the glass. You can try an Anti reflecting coating - either evap / sputter some metal on the glass or you can purchase spin on ARC from Brewer Science. Shay Kaplan Peter Ting wrote: > I had some troubles in doing photolithography on glass > slides, especially when the pattern size is around two > microns. Most patterns were deformed. However, when > silicon wafers instead of glass slides were used as > substrates, everyghing looks fine. Who can tell me why > and how to solve this kind of problem. > Thanks a lot! > Mark > Dept. of Chemistry > Univ. of Washington > > __________________________________________________ > Do You Yahoo!? > Send instant messages & get email alerts with Yahoo! Messenger. > http://im.yahoo.com/ >