Performance and Stability Improvements of Back-Channel-Etched Amorphous Indium–Gallium–Zinc Thin-Film-Transistors by CF4+O2 Plasma Treatment

Abstract

The performance and stability improvement of back-channel-etched amorphous indium–gallium–zinc oxide thin-film transistors (a-IGZO TFTs) by post CF4+O2 plasma treatment is investigated. It is revealed that the metal residue of the wet-etching of source/drain electrodes degrades TFT performance and aggravates the positive threshold voltage ( $V_{\mathrm {th}})$ shift under positive gate bias stress. It is demonstrated that the CF4+O2 plasma treatment effectively removes the metal residue and remarkably improves device performance and the $V_{\mathrm {th}}$ stability. This improvement is attributed to oxygen vacancy repairing at the back channel interface of the a-IGZO TFT by the O free radicals generated by the O2 plasma.