Mechanically flexible vertically integrated a-IGZO thin-film transistors with 500 nm channel length fabricated on free standing plastic foil

We report the first mechanically flexible amorphous Indium-Gallium-Zinc-Oxide (a-IGZO) vertical thin-film transistors (VTFTs) with 500 nm channel length, fabricated on a freestanding plastic foil, using a low temperature process <;150°C. The VTFTs exhibit a well-shaped transfer characteristic, with an on/off current ratio >10
⁷
and a threshold voltage of 2.2 V. We demonstrate full device functionality down to 5 mm bending radius, even after 1000 bending cycles. These results proof that VTFTs are feasible for realizing compact and bendable electronic systems.