Advanced Top-Down Fabrication Process of A-IGZO TFT for Roll-to-Roll Backplane

Amorphous indium-gallium-zinc-oxide (a-IGZO) thin film transistor (TFT) was fabricated by an advanced self-aligned imprint lithography (ASAIL) method with a hybrid etching process. The SAIL is a top-down method to fabricate a TFT using a three-dimensional multilayer etch mask having all pattern information for the TFT. The hybrid etching process was newly applied in the original SAIL process for the purpose of reducing plasma damage of a-IGZO channel layer during plasma etching in the ASAIL process. This research demonstrated that the a-IGZO TFT could be successfully fabricated by the ASAIL process. In particular, the hybrid etching process applied in this paper can be utilized for the back-channel-etch type a-IGZO TFT and further extended for the roll-to-roll backplane process.