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

In this study, N-type amorphous indium zinc oxide thin-film transistors are fabricated and temperature-dependent electrical characteristics in the range of 170-295 K are analyzed through experimental measurements and using an equivalent-circuit model. In this model, thermionic field emission for reverse bias and a thermionic emission mechanism for forward bias are applied. The barrier height coefficient of a contact region between the channel and the Ti/Au electrode is 1.26 meV/K, and the resistance of the channel material decreases at a rate of -0.39Ω · K
^-1
at various temperatures. The obtained energy level is experimentally confirmed through a Kelvin probe measurement. In addition, the simulation results of the channel resistance successfully describe the Arrhenius behavior of the drain current and the Mott variable-range hopping conduction mechanism in a low-temperature regime below 230 K.