초록 |
We demonstrate patterned pentacene OTFTs by the controlled etching of self assembled poly(styrene-b-methyl methacrylate) (PS-b-PMMA) block copolymer gate insulator. Control of both orientation and etching of the cylindrical PMMA microdomain in the polymer layer allow us to fabricate 19 nm thick PS films with hexagonally packed holes of 20 and 38nm in diameter and periodicity, respectively after complete etching of PMMA domains by UV exposure and selective washing with acetic acid on which ca. 60nm pentacene active layer is formed. In addition, since the roughness of gate dielectric over critical value significantly reduces device performances and block copolymer gate dielectric is easily combined with conventional photolithographic techniques using UV exposure, micropatterned gate dielectrics were obtained where the etched regions exhibit very worse device performance, resulting in the isolation of the neighboring TFTs. |