Analysis and Simulation of Low-Frequency Noise in Indium-Zinc-Oxide Thin-Film Transistors

Abstract

Low-frequency noise (LFN) is investigated in a set of indium-zinc-oxide thin-film transistors (IZO TFTs) with fixed channel width ( $W$ = $10~\mu \text{m}$ ) and different channel lengths ( $L\,\,=10$ , 20, 30, and $40~\mu \text{m}$ ) from sub-threshold, linear to saturation regions. The drain current noise power spectral density is measured as a function of effective gate voltage and drain current. The variation slopes of normalized noise with effective gate voltage are in the range of −1.27 and −1.48, which are close to the prediction of the mobility fluctuation mechanism. According to the $\Delta N-\Delta \mu $ model, the flat-band voltage noise spectral density and Coulomb scattering coefficient are extracted. Subsequently, variations of noise with the drain current in the above threshold region are analyzed by considering the band-gap distribution of the tail states. Finally, the BSIM model is also used to model 1/ $f$ noise in the IZO TFTs. The noise parameter $NOIB$ is extracted which is inversely proportional to the effective gate voltage. Good agreements are achieved between the simulated and measured results in the linear region.