Spin coating is the preferred method for application of
thin, uniform films to flat substrates. An excess amount of polymer solution
is placed on the substrate. The substrate is then rotated at high speed
in order to spread the fluid by centrifugal force. Rotation is continued
for some time, with fluid being spun off the edges of the substrate,
until the desired film thickness is achieved. The solvent is usually
volatile, providing for its simultaneous evaporation.
A good reference on spin
W. Flack, D. Soong, A. Bell, and D. Hess, "A mathematical model for
spin coating polymer resists," J. Appl. Phys., 56, 1199 (1984).
An excellent treatment of spin coating of a non-volatile Newtonian liquid can be
S. Middleman and A.K. Hochberg, Process Engineering Analysis in Semiconductor
Device Fabrication, McGraw-Hill, p. 313 (1993)
Suppliers of Spin Coaters