TechNet will not allow sending attachments...but I believe I know what you
are observing...

A thin layer of mask covering metal within the clearance area...yes?

This may be caused by a few process variables.

1- Tack cure too long, making developing difficult - make sure you are tack
curing correctly
2- Poor vacuum during exposure - light/energy may be reflecting under the
areas where it should not, slightly exposing/curing that mask - check that
your vacuum is correct, also, if you are using mylar, check that it is not
dented, damaged, loose, etc.
3- Poor developing, pressure, temperature, chemistry, time in solution, all
may affect this.

My first guess would be developing...

Franklin

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