The effect of a zinc-tin-oxide layer used as an etch-stopper layer on the bias stress stability of solution-processed indium-gallium-zinc-oxide thin-film transistors

作者：Kim Chul Ho^*; Rim You Seung; Kim Hyun Jae

来源：Journal of Physics D: Applied Physics , 2014, 47(38): 385104.

DOI：10.1088/0022-3727/47/38/385104

• thin-film transistors
• dual-active-layered zinc-tin-oxide/indium-gallium-zinc-oxide
• etch-stopper-layer
• back-channel-etch
• wet-etch
• bias stress stability
• solution process

We investigated the bias stress stability of solution-processed indium-gallium-zinc-oxide thin-film transistors (IGZO TFTs) using zinc-tin-oxide (ZTO) as the etch-stopper layer, the so-called dual-active-layered ZTO/IGZO TFT (DALZI TFT). The DALZI TFT can use a low-cost back-channel-etch structure because of the high chemical stability of the upper ZTO layer. The DALZI TFT exhibited only a threshold voltage shift of -1.86V under negative bias illumination stress (NBIS) conditions (stress time = 1000 s), while the unpassivated IGZO TFT suffered from a threshold voltage shift of -19.59V under NBIS conditions (stress time = 1000 s). The superior bias stress stability of the DALZI TFT is attributed not only to the densification effect by the multi-stacking process but also to the lower sensitivity to ambient gases (e.g., oxygen and water vapour) due to the low oxygen vacancy in the upper ZTO layer.

• 出版日期2014-9-24