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

Low-frequency noise (LFN) is investigated in a set of indium-zinc-oxide thin-film transistors (IZO TFTs) with fixed channel width (W = 10 μm) and different channel lengths (L = 10, 20, 30, and 40 μm) 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 ΔN - Δμ 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.