Metal Reaction Doping and Ohmic Contact with Cu-Mn Electrode on Amorphous In-Ga-Zn-O Semiconductor

We investigated the microstructure and electrical properties of Cu and Cu-Mn alloy on amorphous In-Ga-Zn-O (a-IGZO) oxide semiconductor in order to explore a high performance electrode material for thin film transistors (TFTs) in advanced flat panel displays. Current-voltage measurements of metal/semiconductor contact structure showed a non-linear behavior with Cu, while a good ohmic behavior [ ρ C = (1.2−2.9) × 10 −4 Ω·cm 2 ] with the Cu-Mn alloy after annealing at 250°C for 1 h. Transfer and output characteristics of TFT structure also showed excellent performance with the Cu-Mn alloy. The good electrical property was due to the formation of a highly doped n + a-IGZO layer with the carrier density of 1.4 × 10 20 cm −3 . The donor doping could be achieved simply by heat treatment to promote the oxidation of Mn and the reduction of a-IGZO.