Electrical characterization of graphene source/drain electrodes in amorphous indium-gallium-zinc-oxide thin-film transistors subjected to plasma treatment in contact regions

Abstract

In this paper, the electrical characteristics of a-IGZO TFTs with graphene source/drain (S/D) electrodes subjected to argon plasma treatment are analyzed. Depending on the channel length (L), the a-IGZO TFTs showed parasitic resistance dominant (L < 30 μm) and channel conduction dominant regions (L ≥ 30 μm). Using the transmission line method, the intrinsic parameters were extracted. The intrinsic field-effect mobility was about 9.79 cm2 V-1 s-1 and the width-normalized parasitic resistance value was about 460 Ωcm, which are comparable with those of a-IGZO TFTs having S/D plasma-treated regions with no contact metal. Temperature-dependent measurement indicates that the graphene electrodes affected the thermally deactivated behavior of the a-IGZO TFTs, which is different from the case of a-IGZO TFTs having conventional metal electrodes. © 2019 The Japan Society of Applied Physics.