A New Extraction Method of Trap States in Amorphous InGaZnO Thin-Film Transistors

A method to extract the density of subgap states in amorphous InGaZnO thin-film transistors is proposed. The nonuniform characteristic of surface potential along the channel has been taken into account. The variation of interface state density with the applied bias voltage is derived from the capacitance-voltage characteristic. In addition, by combining the obtained density of interface states with the subthreshold swing, the energy distribution of bulk traps is determined. Results fit well with the experimental data.