Investigation of direct inkjet-printed versus spin-coated ZrO(2) for sputter IGZO thin film transistor

In this work, a low leakage current ZrO(2) was fabricated for sputter indium gallium zinc oxide (IGZO) thin-film transistor using direct inkjet-printing technology. Spin-coated and direct inkjet-printed ZrO(2) were prepared to investigate the film formation process and electrical performance for different process. Homogeneous ZrO(2) films were observed through the high-resolution TEM images. The chemical structure of ZrO(2) films were investigated by XPS measurements. The inkjet-printed ZrO(2) layer upon IGZO showed a superior performance on mobility and off state current, but a large V(th) shift under positive bias stress. As a result, the TFT device based on inkjet-printed ZrO(2) exhibited a saturation mobility of 12.4 cm(2)/Vs, an I(on)/I(off) ratio of 10(6), a turn on voltage of 0 V and a 1.4-V V(th) shift after 1-h PBS strain. Higher density films with less oxygen vacancy were responsible for low off state current for the printed ZrO(2) device. The mechanism of deteriorated performance on PBS test can be ascribed to the In-rich region formed at the back channel which easily absorbs H(2)O and oxygen. The absorbed H(2)O and oxygen capture electrons under positive bias stress, serving as acceptors in TFT device. This work demonstrates the film formation process of direct inkjet-printed and spin-coated oxide films and reveals the potential of direct inkjet-printed oxide dielectric in high-performance oxide TFT device. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s11671-019-2905-2) contains supplementary material, which is available to authorized users.