Mechanically stable, flexible, and stretchable metal–insulator–semiconductor‐ferroelectric thin‐film transistors for micro‐LED display applications

Abstract We report flexible and stretchable, ferroelectric thin‐film transistors (FE‐TFTs) based on a metal–insulator–semiconductor‐ferroelectric (MISF) structure. The devices are fabricated on polyimide (PI)/polydimethylsiloxane (PDMS) substrate. During the MISF fabrication process, we could obtain conventional oxide TFTs (SW‐TFTs) by etching out the bottom ferroelectric (FE) layer. This leads to the advantage of fabricating both FE‐TFT and conventional oxide TFT simultaneously. The fabricated FE‐TFTs exhibited a memory window of 9.1 V and showed stable operation under bending on a cylinder of 1 mm radius. The FE‐TFTs were first fabricated on the PI substrate and cut and transferred onto a PDMS substrate to achieve a stretchable device. The devices maintained stable operation under biaxial stretching up to 30% and demonstrated reliable performance for 100 hrs. For display application, we proposed a 3T0C circuit with FE‐TFTs without a capacitor for pulse‐width modulation (PWM) mode in micro‐LED displays. The proposed FE‐TFTs could be used for next‐generation flexible and stretchable displays.