A preferred embodiment of the invention provides a method of spin coating
a liquid, such as a resist, onto a surface of a substrate. An embodiment
of the invention comprises dispensing a liquid onto the surface; spinning
the substrate at a first rotational velocity at least until the liquid
forms a substantially uniform film on the surface of the substrate; and
spinning the substrate at a second rotational velocity in an opposite
direction at least until the liquid reforms a substantially uniform film
on the surface of the substrate. Other embodiments include a first
rotational acceleration for accelerating the substrate to the first
rotational velocity, and a second rotational acceleration for
accelerating the substrate to the second rotational velocity. Preferably,
the second rotational acceleration is much larger than the first
rotational acceleration. Still other embodiments include repeating the
first velocity, second velocity sequence one or more times.