Back Channel Anodization Amorphous Indium Gallium Zinc Oxide Thin-Film Transistors Process

A back channel anodization (BCA) process for fabrication of amorphous indium gallium zinc oxide thin-flim transistors (a-IGZO TFTs) is proposed and demonstrated for the first time. In the BCA process, a localized anodic oxidization (anodization) is successfully implemented to convert the metal layer on back channel into insulator for channel passivation, with the metal layer on source/drain regions intact. As a result, source/drain electrodes and the back channel passivation layer are formed simultaneously in the process step of the BCA. The characterization results show that the fabricated a-IGZO TFTs utilizing BCA process have comparable electrical performances and superior gate-bias stress stability to the conventional a-IGZO TFTs with source/drain electrodes patterned by liftoff.