Highly Robust Bendable Oxide Thin‐Film Transistors on Polyimide Substrates via Mesh and Strip Patterning of Device Layers

Abstract

Advancement in thin‐film transistor (TFT) technologies has extended to applications that can withstand extreme bending or folding. The changes of the performances of amorphous‐indium‐gallium‐zinc‐oxide (a‐IGZO) TFTs on polyimide substrate after application of extreme mechanical bending strain are studied. The TFT designs include mesh and strip patterned source/drain metal lines as well as strip patterned a‐IGZO semiconductor layer. The robustness of the a‐IGZO TFTs with the strain of 2.17% corresponding to the radius of 0.32 mm is tested and no crack generation even after 60 000 bending cycles is found. The split of source/drain electrodes and semiconductor layer can improve the mechanical bending stability of the TFTs. This can be possible by using conventional TFT manufacturing process so that this technology can be easily applied to build robust TFT array for foldable displays.