Step-edge vertical channel organic field-effect transistors (SVC-OFETs) with a very short channel have been fabricated by a novel selective electrospray deposition (SESD) method. We propose the SESD method for the fabrication of SVC-OFETs based on a 6,13-bis(triisopropyl-silylethynyl) pentacene (TIPS-pentacene) semiconductor layer formed by SESD. In the SESD method, an electric field is applied between the nozzle and selective patterned electrodes on a substrate. We demonstrated that the solution accumulates on the selected electrode pattern by controlling the voltage applied to the electrode.

We demonstrated the reduced surface roughness of poly (3-hexylthiophene) (P3HT):(6,6)-phenyl-C61-butyric acid methyl ester (PCBM) thin films with different ratios fabricated by the electrospray deposition (ESD) method. Aggregated structures were observed at the lower voltage, and the uniformity became bad at the higher voltage. Anyway, the minimum root mean square (RMS) roughness was 1.46 nm by optimizing the applied voltage.