Influences of Organic Passivation on performance of Amorphous Indium-Gallium-Zinc-Oxide Thin Film Transistors

Science the first report of indium-gallium-zinc-oxide (a-IGZO) thin-film transistors, it had attracted numerous researchers to explore this new materials [1] . For practical applications, it is critical to gain a stable devices and passivation process could give raise to improvement of stabilities [2] , [3] . In this paper, we investigated the influence of organic passivation layer, parylene, on performance and stability of amorphous indium-gallium-zinc-oxide (a-IGZO) thin-film transistors. The results showed that after deposition of parylene for passivation layer, the subthreshold swing (SS) was reduced as illustrated in Fig. 2 . Besides, we also test the device stability under positive gate bias stress. During PBS, source and drain electrodes are grounded with gate voltage is 15V. Before voltage stress, threshold voltage is obtained by transfer curve in linear region as a reference. And after a specific time scale, the transfer curve was tested again. The obtained threshold voltage evolution with stressed time was shown in Fig. 3 . The improved performance and stability of devices can be contributed to the reduction of trap density in back channel from environment [4] . By capping a passivation layer, the factors such as moisture and oxygen can be excluded from active layer. Usually those molecules working as defect destroy the device performances. This enhanced performance implied parylene-passivated a-IGZO thin-film transistors could be used in the future application of flexible displays.