I use the spin-coater to remove the edge bead.  Just use your normal spin
program and try adding another step such as 1000 rmps for 0.1-0.2 sec at
the end.  This is what I have done, and it seems to work on our system.
Kory

-----Original Message-----
From: Jiang Ziling 

  I have been doing lithography for quite a long time but am still
confused about 'edge bead removal'. My spin-coater has to be closed
when it is spin-coating and there is edge bead on the wafers after
coating. Should I just use something like cotton bud to wipe off the
edge bead on periphery of the wafers? Or is there some clever method
of avoiding edge bead?