Controlled airbrush coating of polymer resists in Roll-to-Roll nanoimprinting with regimented residual layer thickness

We study the effective resist dispensing in continuous Roll-to-Roll (R2R) nanoimprinting system by using a simple and controlled airbrush coating method. Compared to common spin-coating or drop-casting, airbrushing can better afford the continuous coating operation required in a R2R nanoimprinting system with controlled thickness and uniformity. We use a UV-curable epoxysilsesquioxane (SSQ) and propylene glycol methyl ether acetate (PGMEA) as a concentration control agent, which are airbrushed for a controlled time over a continuously fed flexible or rigid substrate in a R2R conveyer. The R2R nanoimprinting is successfully conducted with uniform pattern quality. By modulating the airbrushing time and resist concentration, the residual layer thickness (RLT) of R2R-imprinted patterns can be readily controlled for specific uses.