Temperature dependent Electrical Characterization of Amorphous Indium Zinc Oxide Thin-Film Transistors

Abstract: N-type amorphous indium zinc oxide (a-IZO) thin-film transistors (TFTs) were fabricated and temperature dependent electrical characteristics ranging 170~295K were analyzed via experimental measurement and equivalent circuit model. In the model, thermionic field emission for reverse bias and a thermionic emission mechanism for forward bias were applied respectively. The barrier height coefficient of a contact region between the channel and the Ti/Au electrode is 1.28 meV/K and resistance of the channel material decreases at a rate of -1.06 Ω？K-1 in various temperatures. The obtained energy level was experimentally confirmed through Kelvin probe measurement. And simulation result of the channel resistance successfully describes the Arrhenius behavior of drain current and Mott variable range hopping conduction mechanism in low temperature regime below 230K.