P‐4.4: Multifunctional Laminated Organic Passivation Layer on InSnZnO Thin‐Film Transistors for Enhanced Reliability

Abstract

To improve the stability of the ZnO-based thin-film transistors (TFTs) in multiple environments, we propose a new multifunctional laminated organic passivation layer (MLO PVL) structure for ITZO TFTs. This MLO PVL structure is composed of a self-assembled monolayer (SAM) and an ultraviolet (UV) absorber-modified polydimethylsiloxane (PDMS) layer, which provides the functionality of both passivation layers at the same time. The SAM film could be prepared by vapor-phase treatment, while the UV-absorber-modified PDMS layer could be fabricated using the spin-coating method. Thus, the MLO PVL could be manufactured through a low-temperature and low-cost process. Compared to the unpassivated devices, the MLO-passivated ITZO TFTs exhibit better properties, such as an on-off current ratio (Ion/Ioff) of up to 8.99×10 9 , a field-effect mobility of 19.55 cm 2 V -1 s -1 , and a subthreshold swing (SS) down to 100 mV/dec. Furthermore, the MLO-passivated ITZO TFTs showed an outstanding improvement in the bias stress stability and UV light illumination stress stability with negligible threshold voltage shifts in both positive bias stress (PBS) and positive bias illumination stress (PBIS) tests. This new passivation structure provides a potential strategy for improving the stability of ZnObased TFTs.