Printed via technology for oxide thin film transistors and inverters

Two printed via processes are reported for interconnecting transistors and circuits through dielectric layers. Inkjet printing was used to print corrosive ink materials on dielectric layer, which etch through the dielectric layer to form via holes. Subsequent printing of conductive tracks establishes electric connection between upper and lower levels of circuits. High performance thin-film transistors have been fabricated by printing ITO electrodes and IZO semiconductor channels. The printed transistors were then connected to form inverter circuits through printed via holes. High mobility and high voltage gains were exhibited with the printed transistors and inverters, demonstrating the feasibility of printed via process. The method is scalable to large array of complicated circuits, paving the way to construct integrated circuits in printed electronics.