Hi Bob,
If your nozzle and flow settings are adjusted properly, you should get a
knife-edge profile that reflects the angle of the nozzle.  I am not familiar
with the solvent system of the JSR material, but, as Bernd mentioned, a
PGMEA based EBR should work with most novolak-based resists.  Shipley (now a
division of Rohm & Haas) makes a material called EBR for exactly that
purpose (
http://www.rohmhaas.com/wcm/products/product_detail.page?product=1010163).
Acetone is a problem for many reasons.  The color changes that you see are
probably a result of the redistribution of the resin which causes thickness
changes throughout the film.  Another reason is that acetone could have an
negative effect on the sensitivity of the PAC (or photo-active compound),
which will affect  exposure.  You didn't mention the linewidth you are
trying to achieve, but if you are below 1 um pitch this could be problematic
for you.
Good luck,
Brad


On 3/11/08 12:10 PM, "Bibbotson"  wrote:

> Hi Brad,
>
> Thanks for your answer.  You didn't actually say but I'm assuming from your
> reply that you achieve a nice step at the edge of the resist once the bead
> is removed.
>