Hello David,

Some ideas on where to look......  Is the resist automatically dispensed
or "hand poured (or pipette)?"  Are the defects visible after coat but
before the softbake?  Did the process ever work?

Some of the problems I have encountered:

Dirty coat bowl stirring up dried resist particles.
Poor exhaust - again causing dried resist particles to fly around in the
bowl.
Poor resist dispense - dried resist on the dispense nozzle (or filter or
pump or whatever method used to dispense the chemical). Acetone
splashback caused by edge bead removal or similar.

Feel free to contact me directly; [email protected] for other
suggestions.

Cheers,

Mike