Hi,
       I am experiencing a problem in patterning on silicon-di-oxide wafers; I
am using SHIPLEY 1818 resist to get a thickness of 2.5 micron; 6 seconds of
exposure time. After developing for 60 seconds, I observe, the resist layer
peels off; leaving no patterns on the wafer. Also I had soft-baked the resist at
95 C for 2 minutes in hot-plate.
This seems strange to me, as a month ago, I had successfully transferred the
patterns on to silicon-di-oxide wafers.
I am using mylar film masks.
Please let me know, if any one had experienced similar problems before; and if
so, could you let me know suggestions to solve ?

Thanks

Regards,
Madhav Rao,
Graduate student,
University of Alabama.