Spin coating

Spin coating is a technique for preparation of thin, uniform films, usually of organic polymers. A Solution of a polymer in a volatile solvent is applied on the centre of a rotating, flat substrate. Due to the centrifugal force caused by the fast spinning of the substrate (usually hundreds or thousands of RPMs), the polymer solution is distributed as a thin, homogenous layer of liquid on the substrate area. Because of their low thickness and density together with reasonable mechanical stability, such films can be used as backing or cover for targets or radioactive sources in cases where minimal interference with incoming beam or emitted radiation is required.