A Back-Channel-Etched Amorphous InGaZnO Thin-Film Transistor Technology With Al-Doped ZnO as Source/Drain and Pixel Electrodes

A back-channel-etched fabrication process for amorphous indium-gallium-zinc oxide (a-IGZO) thin-film transistors is proposed, in which an alumium-doped ZnO (AZO) transparent conductive film is used to form both source/drain and pixel electrodes. It is demonstrated that rinsed acetic acid solution has a high etching selectivity over 100:1 between AZO and a-IGZO. In addition, bus and interconnect lines are formed in a separate fabrication step in this process, so that the Cu process could be adopted without bringing contamination issue.