Highly Reliable Flexible Device With Charge Compensation Layer

Abstract

Flexible devices fabricated with polyimide (PI) substrate are crucial for foldable, rollable, or stretchable products in various applications. However, inherent technical challenges remain in mobile charge induced device instabilities and image retention, significantly hindering future technologies. We introduced a new barrier material, SiCOH, into the backplane of amorphous indium-gallium-zinc-oxide (a–IGZO) thin-film transistors (TFTs) that were then implemented into production-level flexible panels. We found that the SiCOH layer effectively compensates the surface charging induced by fluorine ions at the interface between the PI substrate and the barrier layer under bias stress, thereby preventing abnormal positive Vth shifts and image disturbance. The a–IGZO TFTs, metal-insulator-metal (MIM), and metal-insulator-semiconductor (MIS) capacitors with the SiCOH layer demonstrate reliable device performance, Vth shifts, and capacitance changes with an increase in the gate bias stress. A flexible device with SiCOH enables the suppression of abnormal Vth shifts associated with PI and plays a vital role in the degree of image sticking phenomenon. This work provides new inspirations to creating much improved process integrity and paves the way for expediting versatile form-factors.

P‐15: The Back‐channel Effect in Low Temperature Poly‐Si Thin Film Transistors

“…Concurrently, the movement of defect charges and impurity ions within these materials under electric fields contributes to the emergence of a back-channel effect [2][3][4] . This effect, in turn, adversely impacts the stability of the TFT devices, potentially leading to display performance issues like the display mura [5] .…”