Dear all,

I'm trying to coat a 5 inch silicon wafer with a positive resist using a
lab spin coater. However, I'm unable to get a good uniform film. The result
is rainbow-like film. Does anyone know the best spin parameters, i.e spread
speed/time, spin speed/time. I'm dispensing my resist onto the wafer
manually using a syringe. Do I need to completely cover the wafer surface
with the resist? Your kind help is highly appreciated.

Annuar