Oxygen vacancy diffusion in amorphous In-Ga-Zn-Oxide Thin-film-transistors with Ti/Cu source/drain

We investigated the oxygen vacancy diffusion effects on amorphous In-Ga-Zn-Oxide Thin-film-transistors (a-IGZO TFTs) with Ti/Cu source/drain. For a-IGZO TFTs with Ti/Cu source/drain electrode, the on-current and threshold voltage (V_th) shift were almost independent of channel length, in contrast to previous report. Channel resistance of a-IGZO TFTs with Ti/Cu source/drain electrode was reduced due to oxygen vacancy diffusion. Hall mobility of a-IGZO active layer with Ti/Cu source/drain electrode is 14.1 cm²/V sec while that of a-IGZO active layer with Mo source/drain electrode is 1.38 cm²/V sec. Carrier concentration of Ti/Cu electrode is larger than 7.88 times as much as that of Mo electrode. These results show that additional carriers were generated in whole a-IGZO active layer by oxygen vacancy diffusion.