Copper source/drain electrode contact resistance effects in amorphous indium-gallium-zinc-oxide thin film transistors

This paper focuses on the viability of low‐resistivity electrode material (Cu) for source/drain electrodes in thin film transistors (TFTs). The effective resistances between Cu source/drain electrodes and amorphous indium gallium zinc oxide (a‐IGZO) thin‐film transistors were examined. Intrinsic TFT parameters were extracted by the transmission line method (TLM) using a series of TFTs with different channel lengths measured at a low source/drain voltage. The TFTs fabricated with Cu source/drain electrodes showed good transfer characteristics with a field‐effect mobility of 9.64 cm2/Vs, and good output characteristics with steep rise in the low VDS region. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) This paper shows the viability of amorphous indium gallium zinc oxide (a‐IGZO) thin film transistors (TFTs) with copper source/drain electrodes. The transistors exhibit good transfer characteristics with a high field‐effect mobility as well as enhanced output characteristics. The high intrinsic mobility and low contact resistance makes this a very useful material for active‐matrix TFT‐based backplane applications.