Submicron organic thin-film transistors fabricated by film profile engineering method

In this work, we explore and demonstrate the feasibility of a film profile engineering (FPE) concept in fabricating pentacene-based organic thin-film transistors (OTFTs) with submicron channel length. The FPE scheme utilizes a suspended bridge built on the wafer and the specific deposition conditions to form thin films with desirable profiles. In order to form a continuous pentacene channel under the bridge, the background pressure of thermal evaporator is adjusted by pumping down the filling N₂ to a specific level. The results show that, by setting the deposition pressure at 3 mtorr, functional operations of OTFTs with channel length ranging from 0.4 to 0.6μm are obtained.