We have a spinner from "Laurell technology", manually dispence AZ4214.
500rpm,5s--->4000rpm,40s(acceleration=500rpm/s)
After expose with Suss MJB3 alinger, I found PR LW variation of 0.2um
(center wider) from center to edge for 3-inch wafer. At the same time, I
found the PR thickness variation of 0.2um (center thicker).
        Is PR LW variation caused by thickness variation? How to get more
uniform PR thickness, should I use higher spinning speed or higher
acceleration speed?