Abstract
In this paper, the low-temperature ( <= 150 degrees C) fabrication and characterization of flexible indium-galliumzinc-oxide (IGZO) top-gate thin-film transistors (TFTs) with channel lengths down to 280 nm is presented. Such extremely short channel lengths in flexible IGZO TFTs were realized with a novel manufacturing process combining two-photon direct laser writing (DLW) photolithography with Ti/Au/Ti source/drain e-beam evaporation and liftoff. The resulting flexible IGZO TFTs exhibit a saturation field-effect mobility of 1.1 cm(2). V-1. s(-1) and a threshold voltage of 3 V. Thanks to the short channel lengths (280 nm) and the small gate to source/drain overlap (5.2 mu m), the TFTs yield a transit frequency of 80 MHz (at 8.5-V gate-source voltage) extracted from the measured S-parameters. Furthermore, the devices are fully functional when wrapped around a cylindrical rod with 6-mm radius, corresponding to 0.4% tensile strain in the TFT channel. These results demonstrate a new methodology to realize entirely flexible nanostructures and prove its suitability for the fabrication of short-channel transistors on polymer substrates for future wearable communication electronics.