Darren,
Comment on removing PR edge buildup and liftoff: yes, I've had success with
using a razor-blade after spinning to remove edge buildup on average thickness
1.4-micron thick AZ5214E during subsequent exposure in soft contact mode with
100-micron gap on MA-6 mask aligner. This also always eliminated the problem of
my 12 x 16 mm die sticking to photomask. For metallizations thicker than 500-nm,
you can do a google to find a description of a bilayer process using lift-off
resist such as LOR10A followed by image-reversed AZ5214E on top.
Good luck.
Thomas