43‐2: Distinguished Student Paper: High‐Performance, Coplanar Amorphous IGZO TFTs by Spray Pyrolysis on PI Substrate for Low Cost Manufacturing of Foldable AMOLED Display

Abstract

We report a method for low‐cost deposition of bubble‐free and high‐quality amorphous InGaZnO (a‐IGZO) on polyimide (PI) substrate for foldable AMOLED display by spray pyrolysis. The coplanar thin‐film transistor (TFT) with spray‐pyrolyzed (SP) a‐IGZO on PI substrate exhibits VTH of ‐0.8 V, μSAT of 40.95 cm2V‐1s‐1, and SS of 0.18 Vdec‐1 with on/off current ratio of ~108. The TFT shows VTH shift of ‐0.40 V and +0.05 V under tesnsile bending and positive bias temperature stress, respectively. The ring oscillator made of SP a‐IGZO TFTs exhibits an oscillation frequency of 2.38 MHz at VDD of 10 V. The SP a‐IGZO TFT can be used for low‐cost, high‐performance, and flexible display TFT backplanes.