Performance and Stability Improvements of Back-Channel-Etched Amorphous Indium–Gallium–Zinc Thin-Film-Transistors by CF 4 +O 2 Plasma Treatment

The performance and stability improvement of back-channel-etched amorphous indium-gallium-zinc oxide thin-film transistors (a-IGZO TFTs) by post CF4+O-2 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-th) shift under positive gate bias stress. It is demonstrated that the CF4+O-2 plasma treatment effectively removes the metal residue and remarkably improves device performance and the Vth 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 O-2 plasma.