Hi Liang,
   I've had this problem with viscous resists such as some of the OCG
negative resists where you are spinning what looks like cotton candy.
Usually the problem has to do with the vent rate of the spinner. The
resist essentially dries too quickly so you might consider reducing the
vent rate. Also check the age of the resist, if it is too old you may
have lost some solvent.

-Mike
 U. of Louisville
>>> [email protected] 01/28/06 1:06 AM >>>
Hi,everyone

I tried to spin the lift off resist LOR15A on a 40mm
square wafer, but many many residues like hair
appeared out of the wafer edge even at the high speed
of 6000rpm.
Who can give me any advice?