High-performance polymer top-contact thin-film transistor with orthogonal photolithographic process

Abstract

Based on fluorinated photoresist, an orthogonal lift-off process was introduced to directly fabricate patterning metallic source and drain contacts on polymeric thin films to obtain the top-contact structure device. Top-contact polymeric thin-film transistors (TFTs) on the wafer using this orthogonal lift-off process exhibited excellent value of electrical characteristics which was as high as 2.56 cm2V−1s−1 in mobility and >107 in on/off ratio. Compared with Ref. device which was fabricated by shadow mask, this top-contact polymeric TFTs showed the same mobilities but smaller channel length, and the lower contact resistance. In addition, based on fluorinated photoresist, the top-contact polymeric TFTs backplane with photo-patternable expoxy gate insulating layer was also successfully fabricated on glass. The mobility values of this OTFTs with different channel lengths ranged from 0.25 to 0.74 cm2V−1s−1 with an average of 0.48 ± 0.15 cm2V−1s−1 which can be comparable to the Ref. device with epoxy gate insulator using shadow mask method. It was further proved that the availability of such orthogonal photoresists promised to enable the fabrication of high performance OTFT device based the copolymer with long linear alkyl chains.