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 (
$W$
=
$10~\mu \text{m}$
) 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.