Directly lithographic top contacts for pentacene organic thin-film transistors

Recent organic thin-film transistor (OTFT) research has focused on real applications for flat panel displays, smart cards, and smart inventory tags, often based on small molecule organic semiconductors such as pentacene. A resolution of 1 μm in the fabrication of OTFTs is required for these purposes. It has been a major challenge to fabricate top contacts on the organic semiconductors, based on the fact that devices usually have a lower contact resistance than that of organic devices with bottom contacts. In this paper, we report the fabrication process of lithographic source/drain top contacts of pentacene OTFTs with mobility greater than 0.3 CM²/V-s. To our best knowledge this is the first work of directly patterning top contacts on OTFTs and demonstrating the desired performance for applications.